Birthstones

December birthstones are Zircon, Tanzanite, and Turquoise

Natural Zircon Colors

Zircon is a colorful gem with high refraction and fire. Colorless zircon is also known for its brilliance and flashes of multicolored light, called fire. These zircon properties are close enough to the properties of diamond to account for centuries of confusion between the two gems.

Zircon has many beautiful appearances. There are earth tones, cinnamon, sherry, yellow, orange, red and the famous zircon blue colors. Its varied palette of yellow, green, red, reddish-brown, and blue hues makes it a favorite among collectors as well as informed consumers.

Zircon crystals grow in many different types of rock and possess a range of optical and physical properties.

Extensive crystal-structure damage from radioactive elements results in low zircons with much lower optical and physical properties. In extreme cases, they are practically amorphous, which means they lack an orderly crystal structure.

Virtually all the zircons used in jewelry are of the high-value type. A zircon’s classification depends on its properties, which are directly related to the amount of radiation-induced damage done to its crystal structure. Interestingly, radiation-induced crystal-structure breakdown can be reversed somewhat by heating zircon to high temperatures. High-temperature heat treatment repairs the stone’s damaged crystal structure.

Many people have heard of zircon but never seen it. That’s unfortunate because zircon is a beautiful colored stone with its own fair share of folklore and charm. In the Middle Ages, this gem was thought to induce sound sleep, drive away evil spirits, and promote riches, honor, and wisdom.

FACTS

  • MINERAL:Zircon
  • CHEMISTRY:ZrSiO4
  • COLOR:Blue, red, yellow, orange, brown, green
  • REFRACTIVE INDEX:
  • HIGH:925 to 1.984 (+/- 0.040)
  • MEDIUM:875 to 1.905 (+/- 0.030)
  • LOW:810 to 1.815 (+/-0.030)
  • BIREFRINGENCE:000 to 0.059 (low to high)
  • SPECIFIC GRAVITY:90 to 4.73
  • MOHS HARDNESS:6 to 7.5 (low to high)

COLOR

Red and green zircons have market value as collectors’ stones, and cat’s-eye zircons occasionally come on the market as curios. Collectors love zircon’s variety of colors, consumers seem most enamored of just one—blue. Dealers report that at least 80 percent of zircons sold are blue.

CLARITY

Zircons are relatively free of inclusions. But many untreated zircons have a cloudy or smoky appearance. If it’s extreme, it can be a negative factor. Most zircon that is faceted for use in jewelry is free of inclusions visible to the eye. Zircons with eye visible inclusions will drop in value.

CUT

Cutters usually fashion zircon in the brilliant style to take advantage of its luster and fire. Zircon can also be found in step cuts, which have rows of parallel facets, and mixed cuts, which are a combination of brilliant and step-cut facets.

CARAT WEIGHT

The supply of zircon is generally limited, and typical sizes depend on color. Blue or green stones normally range from 1 carat to 10 carats and yellows and oranges up to around 5 carats. Reds and purples are usually smaller.

(Gem Encyclopedia – Zircon, 2016)

 

Antique Cushion-Shaped Tanzanite

Tanzanite – Lush blue velvet, rich royal purple; exotic Tanzanite is only found one place on earth, in Tanzania, near Kilimanjaro.

Tanzanite’s appearance is influenced greatly by its pleochroism, which is the ability of a gemstone to show different colors when viewed in different crystal directions. Tanzanite can be violet-blue, similar to a sapphire color, or much more purplish. Often, both colors are readily visible in a stone when it is gently rocked and tilted.

Tanzanite is relatively new to the colored stone galaxy. in 1967 a Masai tribesman stumbled upon a cluster of highly transparent, intense blue crystals weathering out of the earth in Merelani, an area of northern Tanzania. He alerted a local fortune hunter, who quickly registered four mining claims. The fortune hunter hoped he’d been shown a new sapphire deposit; however, the deposit contained one of the world’s newest gems.

Within a short time, 90 more claims appeared in the same 20-square-mile area. No one was quite sure what the beautiful crystals were, but everyone wanted to lay claim to the profits they were certain to produce.

Almost overnight, tanzanite was popular with leading jewelry designers and other gem professionals, as well as with customers who had an eye for beautiful and unusual gems. The instant popularity of this transparent blue to violet to purple gem was tied to its vivid color, high clarity, and potential for large cut stones.

QUALITY FACTORS

COLOR A deep saturated blue is the most valuable color of tanzanite. Paler tones are more affordable. Untreated, tanzanite is typically brownish. Most blue tanzanites for sale today owe their color to heat treatment, which is what reveals its attractive blues and violets. The blue crystals originally discovered by Masai tribesmen were an exception because they’d probably been exposed to a natural heat source within the earth at some point.

CLARITY Eye-visible inclusions decrease the value of tanzanite, particularly in lighter colored stones.

CUT Tanzanite is available in a wide range of shapes but cushion and oval cuts are most common.

CARAT WEIGHT Tanzanite is available in a wide variety of sizes, shapes, and faceting designs. The finest and deepest colors are usually seen in sizes over 5 carats. Smaller stones are often less intense in color.

FACTS

MINERAL: Zoisite

CHEMISTRY: Ca2Al3(SiO4)3(OH)

COLOR: Blue to violet to bluish purple

REFRACTIVE INDEX: 1.691 to 1.700

BIREFRINGENCE: 0.008 to 0.013

SPECIFIC GRAVITY: 3.35

MOHS HARDNESS: 6 to 7

(Gem Encyclopedia – Tanzanite, 2016)

 

 

November Birthstone is Citrine

CITRINE

Citrine is the transparent, pale yellow to brownish orange variety of quartz.

 

ABOUT CITRINE

Citrine is rare in nature. In the days before modern gemology, its tawny color caused it to be confused with topaz. Today, its attractive color, plus the durability and affordability it shares with most other quartzes, makes it the top-selling yellow-to-orange gem. In the contemporary market, citrine’s most popular shade is an earthy, deep, brownish or reddish orange. A trace of iron in citrine’s structure is responsible for its yellow-to-orange color.

Since natural citrine is rare, most of the citrine on the market is the result of heat treatment, which causes some amethyst to change color from undesirable pale violet to an attractive yellow. The amethyst’s original hue can determine the richness of the resulting citrine’s yellow color.

Citrine crystals occur in a wide range of sizes, and citrine sizes up to 20 carats are readily available in jewelry. Although citrine is available in standard shapes and sizes, many high-end jewelry designers and gem carvers have fashioned the warm yellow gem into unusual cuts for jewelry and carvings.

Citrine History and Lore

People have used quartz in jewelry for thousands of years. Egyptians gathered ornately striped agates from the shore and used them as talismans, the ancient Greeks carved rock crystal ornaments that glistened like permafrost, and the hands of Roman pontiffs bore rings set with huge purple amethysts. Natural citrine is rare, and today most citrine quartz is the result of heat treatment of amethyst quartz. Even so, gems from the Victorian era have surfaced, and it’s not hard to imagine that citrine was treasured even in earlier times.

 

WHY WE LOVE THIS GEMSTONE

AFFORDABLE

Even fine citrine has a modest price tag. Large gems remain affordable, as price per carat does not rise dramatically for larger sizes.

AMETRINE

In Bolivia, amethyst and citrine colors can occur together in the same crystal. These unique gems are called ametrine.

QUALITY FACTORS

The following factors combine to determine a citrine’s value.

COLOR Vivid yellows, reddish oranges, and earth tones are popular with consumers.

CLARITY Eye-visible inclusions are not common in citrine. If present, they decrease its value.

CUT Citrine might be carved, custom-cut, or calibrated for jewelry use.

CARAT WEIGHT Citrine is available in a wide range of sizes for setting into a variety of jewelry styles.

 

FACTS

MINERAL: Quartz

CHEMICAL COMPOSITION: SiO2

COLOR: Yellow to orange to orangy red

REFRACTIVE INDEX: 1.544 to 1.553

SPECIFIC GRAVITY: 2.66 (+0.03/-0.02)

MOHS HARDNESS: 7

 

Citrine Gemstone | Natural Citrine Stone – GIA http://www.gia.edu/citrine#.V9ldQvkrLcv

October Birthstone is Opal

Opal is considered an October birthstone. Some people think it’s unlucky for anyone born in another month to wear an opal. That superstition comes from a novel written in the 1800s (Anne of Geierstein) by Sir Walter Scott), and not from any ancient belief or experience. In fact, throughout most of history, opal has been regarded as the luckiest and most magical of all gems because it can show all colors.

Because opal has the colors of other gems, the Romans thought it was the most precious and powerful of all. The Bedouins believed that opals contained lightning and fell from the sky during thunderstorms. Writers have compared opals to volcanoes, galaxies, and fireworks.

Opal is the product of seasonal rains that drenched dry ground in regions such as Australia’s semi-desert “outback.” The showers soaked deep into ancient underground rock, carrying dissolved silica downward. During dry periods, much of the water evaporated, leaving solid deposits of silica in the cracks and between the layers of underground sedimentary rock. The silica deposits formed opal.

Opal is known for its unique display of flashing rainbow colors called play-of-color. There are two broad classes of opal: precious and common. Precious opal displays play-of-color, common opal does not.
Play-of-color occurs in precious opal because it’s made up of sub-microscopic spheres stacked in a grid-like pattern—like layers of Ping-Pong balls in a box. As the light-waves travel between the spheres, the waves diffract breaking into the colors of the rainbow, called spectral colors.

FACTS

  • MINERAL: Hydrated Silica
  • CHEMISTRY: SiO2nH2O
  • COLOR: All colors
  • REFRACTIVE INDEX: 37-1.47
  • BIREFRINGENCE: None
  • SPECIFIC GRAVITY: 15 (+0.08, -0.90)
  • MOHS HARDNESS: 5 to 6.5

 

 

Individual opals can vary widely in appearance and quality. As diverse as snowflakes or fingerprints, each gem can differ noticeably.

What to look for:

Color Color refers to background color and play-of-color. Pattern is arrangement of play-of-color.

Clarity With an opal, clarity is its degree of transparency and freedom from inclusions.

Cut The cutter considers an opal’s color, pattern, and clarity when planning the finished gem. Exceptional opals might not be cut to standard sizes and shapes. Domed surfaces give the best play-of-color.

Carat Common sizes for many of the opal cabochons set in jewelry are 6×4, 7×5, and 8×6 mm. Opal however comes in a wide range of sizes.

Caring for your opal:

Durability– Opal is a gem suitable for jewelry but requires care when wearing to not scratch or break the stone.

Care and Cleaning– Warm soapy water is always safe. Don’t expose an opal to extreme light, heat, or dryness even though most opals are cured to make sure it won’t crack.

Treatment– Opals can be treated by impregnation with oil, wax, or plastic, and by surface modifications.

 

Opal Gemstone | Opal Stone – GIA. (n.d.). Retrieved July 27, 2016, from http://www.gia.edu/opal

September Birthstone is Sapphire

Sapphire is the birthstone for September and the gem of the 5th and 45th anniversaries.

Blue sapphire belongs to the mineral species corundum. It can be a pure blue but ranges from greenish blue to violet-blue. The name “sapphire” can also apply to any corundum that’s not red and doesn’t qualify as ruby. These include fancy sapphires and can come in violet, green, yellow, orange, pink, purple, and intermediate hues. Some sapphires display the phenomenon known as color change, most often going from blue in daylight or fluorescent lighting to purple under incandescent light. Sapphires can even be gray, black, or brown.

Fancy sapphires are generally less available than blue ones, with some colors being scarce, especially in extreme sizes. Yet fancy sapphires create a rainbow of options for people who like the romance associated with this gem, but who also want something unique.

The mineral corundum is composed only of aluminum and oxygen, and it requires a growth environment that’s free of silicon. However, silicon is a very common element, making natural corundum somewhat rare. In its purest state, corundum is actually colorless. Colorless sapphires were once popular diamond imitations, and they’ve staged a comeback as accent stones in recent years. Most corundum contains color-causing trace elements. When the trace elements are iron and titanium, the corundum is blue sapphire.

Corundum can show a phenomenon called asterism, or the star effect. This phenomenon usually appears as a six-ray star pattern across a cabochon-cut stone’s curved surface. The star effect can be seen in ruby or any color of sapphire, and it arises from white light reflecting from numerous tiny, oriented needle-like inclusions.

Besides fancy sapphire and star corundum, there’s another interesting variety: color-change sapphire. These fascinating stones change color under different lighting. Their presence adds a special dimension to the already amazing corundum family of gems.

Both blue and fancy sapphires come from a variety of exotic sources including Madagascar, Tanzania, Sri Lanka, Myanmar, and Australia.

In folklore, history, art, and consumer awareness, sapphire has always been associated with the color blue. Most jewelry customers think all sapphires are blue, and when gem and jewelry professionals use the word “sapphire” alone, they normally mean “blue sapphire.”

FACTS

MINERAL: Corundum

CHEMISTRY: Al2O3

COLOR: Every color but red

REFRACTIVE INDEX: 1.762 to 1.770

BIREFRINGENCE: 0.008 to 0.010

SPECIFIC GRAVITY: 4.00

MOHS HARDNESS: 9

Sapphire is one of the Big 3 of jewelry gemstones—the other two are ruby and emerald.

Color The most highly valued blue sapphires are velvety blue to violet-blue, in medium to medium dark tones. Preferred sapphires also have strong to vivid color saturation. The saturation should be as strong as possible without darkening the color and compromising brightness.

Clarity Blue sapphires often have some inclusions. Blue sapphires with extremely high clarity are rare, and very valuable. Price can drop if the inclusions threaten the stone’s durability.

Cut To achieve the best overall color, maintain the best proportions, and retain the most weight possible, cutters focus on factors like color zoning, pleochroism, and the lightness or darkness of a stone.

Carat- Blue sapphires can range in size anywhere from a few points to hundreds of carats, and large blue sapphires are more readily available than large rubies. However, most commercial-quality blue sapphires weigh less than 5.00 carats.

Caring for your sapphire- Keep your sapphire beautiful by following simple care and cleaning guidelines.

Durability Corundum (ruby and sapphire) is relatively hard and tough; a great choice for daily worn jewelry.
CARE AND CLEANING Warm soapy water is always safe.
TREATMENT Fracture-filled, cavity-filled, or dyed material should only be cleaned with a damp cloth.

Sapphire Gemstone | Sapphire Stone – GIA. (2016, July 27). Retrieved July 27, 2016, from http://www.gia.edu/sapphire

August Birthstone is Peridot

Peridot is the birthstone for August and the 15th anniversary gemstone.

Found in lava, meteorites, and deep in the earth’s mantle, yellow-green peridot is the extreme gem.

The word peridot comes from the Arabic “faridat,” which means “gem.” Most peridot formed deep inside the earth and was delivered to the surface by volcanoes. Some also came to earth in meteorites, but this extraterrestrial peridot is extremely rare, and not likely to be seen in a retail jewelry store.

Gem miners find peridot as irregular nodules (rounded rocks with peridot crystals inside) in some lava flows in the United States, China, and Vietnam and, very rarely, as large crystals lining veins or pockets in certain types of solidified molten rock.  Geologists believe these deposits relate to the spreading of the sea floor that occurs when the earth’s crust splits, and rocks from its mantle are pushed up to the surface. Sometimes these rocks can be altered, deformed, and incorporated into mountain ranges by later earth movements.

Peridot color ranges from a brown-green color to yellowish green to pure green. Yellowish green is the most common peridot color seen in jewelry.

Peridot is the gem variety of the mineral olivine. Its chemical composition includes iron and magnesium, and iron is the cause of its attractive yellowish green colors. The gem often occurs in volcanic rocks called basalts, which are rich in these two elements.

Color Although the best peridot is a pure grass green, most peridot is yellowish-green.  The pure grass green color, is usually only achieved in gems of 10-cts. or larger. Smaller examples tend to show yellowish-green hues and brown undertones lower the value of peridot.

Clarity The best-quality peridot has no eye-visible inclusions, with perhaps a few tiny black spots visible under magnification. Other inclusions common in peridot are reflective, disk-shaped inclusions called “lily pads.”

 Cut  Peridot can be a stunning gem with skilled cutting to maximize its beautiful color. It’s available in a wide variety of shapes and cutting styles, including ovals, pears, rounds, emerald cuts, cushion cuts, triangle cuts, and marquise shapes.

Carat Weight Although the finest gems are generally seen in sizes above 10-cts. and there are fine gems of more than 50-cts. on the market, smaller gems cut to standard sizes are affordable and readily available.

Caring for your peridot

  1. Durability Peridot is durable enough for jewelry wear but should be worn with some care so as not to scratch it.
  2. CARE AND CLEANING Warm soapy water is always safe.
  3. TREATMENT Peridot is rarely treated, but might have fractures. Only clean fracture-filled gemstones with warm, soapy water.

   FACTS

  • MINERAL: Olivine
  • CHEMISTRY: (MgFe)2SiO4
  • COLOR: Yellowish green
  • REFRACTIVE INDEX: 1.65 to 1.69
  • BIREFRINGENCE: 0.035 to 0.038
  • SPECIFIC GRAVITY: 3.34
  • MOHS HARDNESS: 6.5 to 7

 “Peridot Gemstone | Peridot Stone – GIA.” Peridot Gemstone | Peridot Stone – GIA. N.p., n.d. Web. 27 July 2016.

July Birthstone is Ruby

Ruby is the birthstone for July and the gem for the 15th and 40th anniversaries.

Ruby can command the highest per-carat price of any colored stone, making it one of the most important gems in the colored stone market. In its purest form, the mineral corundum is colorless. Trace elements such as Chromium become part of the mineral’s crystal structure cause ruby’s red color. The strength of ruby’s red depends on how much chromium is present—the more chromium, the stronger the red color. Chromium can also cause fluorescence, which adds to the intensity of the red color.

Red is the color of our most intense emotions—love and anger, passion and fury. It’s associated with objects of power and desire—like fast cars and red roses. Early cultures treasured rubies for their similarity to the redness of the blood that flowed through their veins, and believed that rubies held the power of life.

Ruby is one of the most historically significant colored stones. Rubies are mentioned four times in the Bible, in association with attributes like beauty and wisdom. In the ancient language of Sanskrit, ruby is called ratnaraj, or “king of precious stones.” Ruby has been called the most precious of the 12 stones created by God.

Desire for ruby is just as great today as it always has been. As a symbol of passion, ruby makes an ideal romantic gift. Consumers are drawn to the lush color because it also signifies wealth and success.

Color is the most important quality factor for ruby

The finest ruby has a pure, vibrant red to slightly purplish red color. As the color becomes too orangy or more purplish, the ruby moves down in quality. The highest-quality rubies have vivid color saturation. The color must be neither too dark nor too light to be considered finest quality.

Clarity

People in the trade expect rubies to have at least some inclusions because inclusion-free rubies are rare. Ruby value depends on how visible the inclusions are. Obvious inclusions or inclusions that reduce transparency or brightness lower a ruby’s value dramatically.

Cut

Several factors affect the cut and proportion of rubies on the market. A ruby’s crystal shape dictates its suitability for certain cuts. The most common shape is a flat tabular hexagonal shape, but ruby crystals from some sources can be elongated.

Carat

Fine-quality rubies over one carat are very rare, but commercial-quality rubies are commonly available in a wide range of sizes. The price per carat goes up significantly for ruby as it increases in size.

TIPS & ADVICE

  1. Work with a jeweler you trust.

Judging the quality of ruby requires expertise. Look for gemological credentials. A jeweler who knows and loves ruby will have several to show you so you can see quality differences side by side.

  1. Don’t confuse origin with quality.

Even the best mines produce low-quality material. Where a ruby comes from is no guarantee of value or quality. Fine-quality rubies can come today from several countries.

  1. Ask about treatment.

Most rubies have been heated, and some gems on the market also have had color diffused into the surface or fractures filled with lead glass to improve their appearance. When shopping, ask about treatment information included in writing.

  1. When in doubt, get a lab report.

A report from an independent laboratory like GIA can confirm that the ruby you are buying is natural and tell you whether there is evidence of treatment.

FACTS

  • MINERAL:Corundum
  • CHEMICAL COMPOSITION:Al2O3
  • COLOR:Red
  • REFRACTIVE INDEX:762 to 1.770
  • BIREFRINGENCE:008 to 0.010
  • SPECIFIC GRAVITY:00 (+/- 0.05)
  • MOHS HARDNESS:9

(Gem Encyclopedia Ruby)

 

June Birthstone is Alexandrite

Alexandrite is a birthstone for June, along with pearl and moonstone. Alexandrite is also the gem for the 55th wedding anniversary.

Alexandrite, with its chameleon-like qualities, is a rare variety of the mineral chrysoberyl. Its dramatic color change is sometimes described as “emerald by day, ruby by night.” Other gems also change color in response to a light-source change, but this gem’s transformation is so striking that the phenomenon itself is often called “the alexandrite effect.”

Alexandrite is also a strongly pleochroic gem, which means it can show different colors when viewed from different directions. Typically, its three pleochroic colors are green, orange, and purple-red. However, the striking color change doesn’t arise from the gem’s pleochroism, but rather from the mineral’s unusual light-absorbing properties.

Because of its scarcity, especially in larger sizes, alexandrite is a relatively expensive member of the chrysoberyl family. It shares its status as a June birthstone with cultured pearl and moonstone. The gem was named after the young Alexander II, heir apparent to the throne. It caught the country’s attention because its red and green colors mirrored the national military colors of imperial Russia.

Color

Change is the most important quality factor for alexandrite.

The most-prized alexandrites show a strong color change from bluish green in daylight and red to purplish red in incandescent light, with moderately strong to strong color saturation.

Clarity

Alexandrites tend to contain few inclusions. There’s a dramatic rise in value for clean material with good color change and strong hues. Rarely parallel needle-like inclusions create a cat’s-eye phenomenon, increasing the alexandrite’s value.

Cut

Alexandrites are most often fashioned as mixed cuts, which have brilliant-cut crowns and step-cut pavilions. When cutting alexandrite, cutters orient the gem to show the strongest color change through the crown.

Carat

Most fashioned alexandrites are small, weighing less than one carat. Larger sizes and better qualities rise in price dramatically: Fine-quality stones in sizes above 5.0 carats are very expensive.

TIPS & ADVICE

  1. If it seems too good to be true, it probably is. Natural alexandrite is rare and valuable. An inexpensive gem with a strong red-green color change is likely to be a synthetic or simulant.
  2. Judging the quality of alexandrite requires expertise. Look for gemological credentials. A jeweler who knows and loves alexandrite will welcome the challenge to find one that’s right for you.
  3. When in doubt, get a lab report. For a significant purchase an independent laboratory report can confirm that the alexandrite you are buying is natural.
  4. Don’t expect to be able to match alexandrites easily.

Creating pairs or suites of alexandrite for earrings, a three stone ring, or a necklace is very challenging. Matching size, shape, color, and color change is particularly difficult.

 FACTS

  • MINERAL: Chrysoberyl
  • CHEMISTRY: BeAl2O4
  • COLOR: Bluish green in daylight, purplish red in incandescent light
  • REFRACTIVE INDEX: 746 to 1.755
  • BIREFRINGENCE:008 to 0.010
  • SPECIFIC GRAVITY:73
  • MOHS HARDNESS:5

(Gem Encyclopedia Alexandrite)

May Birthstone is Emerald

Emerald is the birthstone of May and the gem of the twentieth and thirty-fifth wedding anniversaries.

Emerald is the gem that is always associated with the lushest landscapes and the richest greens; Ireland is known as the Emerald Isle. The first known emerald mines were in Egypt, dating from at least 330 BC into the 1700s. Cleopatra was known to have a passion for emerald, and used it in her royal adornments.

Emerald is the most famous member of the beryl family. Legends endowed the wearer with the ability to foresee the future when emerald was placed under the tongue, as well as to reveal truth and be protected against evil spells. Emerald was once also believed to cure diseases like cholera and malaria. Wearing an emerald was believed to reveal the truth or falseness of a lover’s oath as well as make one an eloquent speaker.

Color

The most important quality factor for emerald is color. Emerald is the green to greenish blue variety of beryl, a mineral species that also includes aquamarine as well as beryls in other colors. The most important quality factor of emerald is color, with the most desirable colors being bluish green to pure green, with vivid color saturation and tone that’s not too dark. The most-prized emeralds are highly transparent with evenly-distributed color.

Clarity

Emeralds typically contain inclusions that are visible to the naked eye. Because of this, many understand and accept the presence of inclusions in emeralds. Eye-clean emeralds are especially valuable because they’re so rare.

Cut

Cut is one of the most important factors in appearance. The most popular cut is the emerald shape due to the original shape of the crystals. Well cut stones maximize the beauty of the color while minimizing the impact of fissures, and creating a bright, lively stone.

Carat

Fashioned emeralds come in a wide range of sizes. There are emeralds in museums and private collections that weigh hundreds of carats. Quality-for-quality, the price of emerald can rise dramatically as the size increases.

Durability

Heat, light, and chemicals can damage the materials used to fill surface-reaching fractures.

Care and cleaning

Warm soapy water is always safe.

Treatment

Most emeralds contain filled fractures; it’s risky to clean them ultrasonically or with steam.

FACTS

  • MINERAL: Beryl
  • CHEMISTRY: Be3Al2Si6O18
  • COLOR: Vibrant green
  • REFRACTIVE INDEX: 577 to 1.583
  • BIREFRINGENCE: 005 to 0.009
  • SPECIFIC GRAVITY: 72
  • MOHS HARDNESS: 5 to 8

(Gem Encyclopedia Emerald)

April Birthstone is Diamond

Diamond is the birthstone for April and the gemstone that marks the 60th and 75th wedding anniversary.

Diamonds are among nature’s most precious and beautiful creations. Diamond is the hardest gem of all, formed from one element, carbon, under high temperature and pressure conditions deep below the earth’s surface. Diamond is the hardest material on earth; 58 times harder than any other natural material.

In 2002, a coalition of governments, non-governmental organizations, and the diamond industry established the Kimberley Process to control the export and import of rough diamonds to eliminate the trade in conflict diamonds. Today 99% of diamonds in the marketplace are conflict free.

Color

The amount of a diamond’s color is rated on a scale of D – Z. Gemologists measure the colorlessness of a diamond to rate the color.

Clarity

Clarity grades are based on the number, size, relief, and positions of inclusions that can be seen under 10x magnification.

Cut

Diamond cuts affect their brilliance, fire, and scintillation. Precise cutting is necessary to provide maximum effect to its proportions and symmetry. The number of facets affects the pattern of the reflections in a diamond rather than overall brightness. Diamonds with more facets have more numerous smaller reflections instead of fewer larger reflections. Brightness is a function of proportions, polish and symmetry, not the number of facets.

Carat

Diamonds are sold by weight. One carat equals 0.20 grams. One in 1,000 diamonds weighs more than one carat.

Durability

Sudden and extreme temperature changes threaten a diamond’s stability

Care and Cleaning

Diamonds can be cleaned safely by using warm water and a mild soap with a soft toothbrush. It is recommended to have your diamond cleaned professionally at least once a year.

Treatment

Diamond color and clarity treatments can be affected by heat and chemicals.

FACTS

  • MINERAL: Diamond
  • CHEMISTRY: C
  • COLOR: Colorless
  • REFRACTIVE INDEX: 2.42
  • BIREFRINGENCE: None
  • SPECIFIC GRAVITY: 3.52 (+/-0.01)
  • MOHS HARDNESS: 10

(Gem Encyclopedia Diamond)

March Birthstone is Aquamarine

Aquamarine is the birthstone for March and the gem of the 19th wedding anniversary.

The name “aquamarine” is derived from two Latin words:  aqua, meaning “water,” and marina, meaning “of the sea.” March’s birthstone was thought to keep sailors safe at sea and calm the sea’s waves; it was also believed to enhance the happiness of marriages. It has been said that the mineral beryl gives the wearer protection against foes in battle or litigation. It makes the wearer unconquerable and amiable, and also quickens the intellect.

Aquamarine is a blue to slightly greenish-blue variety of the mineral beryl. The best aquamarines combine high clarity with translucent transparency. Crystals are sometimes big enough to cut fashioned gems of more than 100 carats.

Color

Aquamarine is pastel blue, greenish blue, or green-blue. The preferred aquamarine color is a dark blue to slightly greenish blue with moderate intensity and is most striking in gems of over 5-cts. Fine stones show even blue color with no zoning. If you prefer an aquamarine color that has more green in it, you can buy a beautiful gem for less than you would pay for the same gem if it was a pure blue. Aquamarine’s color gets more intense as it gets larger. It is very difficult to find small sizes with saturated color: most stones below a carat in size have a pale color.

Clarity

Most faceted aquamarines are free of eye-visible inclusions. Collectors generally expect clean gems with good transparency. There is a trend today to use included, but good-color aquamarines as unique centerpieces for jewelry articles or even as partially polished crystal slices or nuggets in necklaces. Although aquamarine is the mineral beryl, like emerald, inclusions are much less accepted than they would be in emerald. Aquamarine that is milky or included is much less expensive, although it may be beautiful in its own way.

Cut

Aquamarines can be cut into almost any shape, but cutters often fashion them as emerald cuts or as round or oval brilliants. Many gem artists use aquamarine for one-of-a-kind designer cuts because their styles maximize the material’s pure, even color and high clarity.

Carat

Aquamarine is available in large sizes—many fine gems of 25-cts or greater are readily available. Generally, smaller accent sizes are pale: cut gems are more likely to have a darker color if they are larger than five carats.

Durability

Aquamarine is durable. It is a good choice for rings and mountings for everyday wear.

Care and Cleaning

Clean Aquamarine with warm soapy water.

Treatment

Heat treatment of aquamarine is stable, but fracture-filled gems should only be cleaned with warm soapy water.

FACTS

  • MINERAL: beryl
  • CHEMISTRY: Be3Al2Si6O18
  • COLOR: greenish blue, light in tone
  • REFRACTIVE INDEX: 1.577 to 1.583
  • BIREFRINGENCE: 0.005 to 0.009
  • SPECIFIC GRAVITY: 2.72
  • MOHS HARDNESS: 7.5 to 8.0

(Gem Encyclopedia Aquamarine)