Gemstones

Here you will find useful information on origin, treatments, and ways to care for your gemstone jewelry.

The Mohs' Scale of Hardness

The Mohs' Scale of Hardness measures the hardness of a mineral (gemstone). The minerals are tested through scratching and harder minerals scratch softer ones. The scale ranges from 1-10, 1 being the softest and ten being the hardest.

Hardness Gem
2.5 (soft)Pearl
3Pearl
3.5Pearl
4Pearl
4.5Pearl
5Turquoise
5.5Opal, Turquoise
6Opal, Tanzanite, Turquoise
6.5Garnet, Jade, Peridot, Tanzanite
7Amethyst, Citrine, Garnet, Jade, Peridot, Tanzanite, Tourmaline
7.5Aquamarine, Emerald, Garnet, Tourmaline
8Emerald, Topaz
8.5
9Ruby, Sapphire
9.5
10 (hard)Diamond

Amethyst

amethyst

Traditional birthstone for February

Amethyst is the most valued member of the quartz family. Fine quality amethysts can range from dark, reddish purple to pale lilac. They can also be found in a pale mint green. Some paler amethysts are almost colorless in daylight.

Amethysts are mined all over the world, the majority from Lower Australia, Brazil and other South American countries. Zambia, South Korea, Russia, India, Canada and the United States also produce amethysts. Amethysts have a hardness of 7 on the Mohs' Scale of Hardness.

Amethysts can be cleaned with warm soapy water and a soft brush. Ultrasonic cleaners should be used with care as they may damage the stone. Amethysts can become paler if kept out in the sun.

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Aquamarine

aquamarine

Traditional birthstone for March

Aquamarine belongs to the beryl family. It comes in various shades of blue, from an almost colorless pale blue, to blue-green, to teal. The most valued is a deep-blue aqua color.

Aquamarines are found in the United States, Columbia, Brazil, Russia, South Africa, Rhodesia, India, Pakistan, Zambia, and Ceylon. Aquamarines have a hardness of 7.5 on the Mohs' Scale of Hardness.

Aquamarines can be cleaned with warm soapy water and a soft brush. Ultrasonic cleaners should be used with care as they may damage the stone.

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Citrine

citrine

Traditional birthstone for November

Citrine is one of the more rare forms of quartz. Named for its lemon-yellow color, citrine can range from pale yellow, to golden brown, to a dark orange reddish brown.

Most citrine is mined in Brazil. Madagascar, Bolivia, Russia and France are among the countries where citrine is also mined. Citrine has a hardness of 7 on the Mohs' Scale of Hardness.

Citrinescan be cleaned with warm soapy water and a soft brush. Ultrasonic cleaners should be used with care as they may damage the stone.

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Diamond

diamond

Traditional birthstone for April

Most diamonds range from colorless to tinted yellow or brown. Naturally-occurring colors such as blue, yellow, green, pink and red are extremely rare and prohibitively expensive; consequently, color enhancement treatments are used to create a variety of colors. Treatments include laser drilling and filling, irradiation and heating. These are common industry practices, and the gems are considered to be one-hundred percent diamonds. The value of a diamond is determined by its Cut, Color, Clarity and Carat, also known as the "Four C's".

Diamonds are mined in Australia, Republic of Congo, Canada, Russia, South Africa, Botswana and Namibia. Diamonds have a hardness of 10 on the Mohs' Scale of Hardness, making it the hardest naturally-occurring stone.

Diamond jewelry should be stored separately from other jewelry. It is recommended to place them in velvet or silk. Diamonds can be cleaned with steamers, ultrasonic cleaners or warm soapy water.

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Emerald

emerald

Traditional birthstone for May

Emeralds also belong to the beryl family. Colors range from yellow green to grass green, and deep shades of green with blue tinges. Emeralds are softer stones based on jewelry standards; they should not be used for everyday wear. They are usually treated to reduce the visibility of cracks and inclusions, and also to improve their clarity. Another common practice in the jewelry industry is to oil or enhance the emerald with colorless resins.

Colombia continues to be the top country in which fine emeralds are found. Emeralds are also found in other parts of South America, Egypt, Brazil, Russia, South Africa,India, Pakistan andRhodesia. Emeralds have a hardness of 7.5 - 8 on the Mohs' Scale of Hardness.

Emeralds are delicate stones which should be very well taken care of when wearing or cleaning them. They should never be steam cleaned or immersed in ultrasonic bath. Emeralds should be professionally re-oiled every few years.

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Garnet

garnet

Traditional birthstone for January

Garnets belong to the nesosilicates family. Usually only thought of as dark red, garnets can range from colorless to near black, occurring in all colors except blue. Most varieties are named for their color.

Garnets are found in the U.S., South Africa, Argentina, Australia, Brazil, Burma, Scotland, Switzerland and Tanzania. Garnets have a hardness of 6.5 - 7.5 on the Mohs' Scale of Hardness.

Garnets can be cleaned with warm soapy water and a soft brush. Ultrasonic cleaners are safe for most garnets. They should not be steam cleaned.

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Jade

jade

Jade belongs to two mineral families - nephrite and jadeite. The color and translucence of the jade determines its value, with green being the most well-known color, and lavender the rarest. Other varieties include milky white, violet, yellow, red, and brownish-black. Most modern jade is wax-treated.

Jade can be found in Taiwan, Australia, Canada, Myanmar (Burma), New Zealand, Mexico, South and Central America, China, and the US. Jade has a hardness of 6.5 - 7 on the Mohs' Scale of Hardness.

Use a soft damp cloth to clean jade. It can also be cleaned with warm soapy water and a soft brush.

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Opal

opal

Modern birthstone for October

Opals can display a range of colors in what is called the play-of-color, or the streaks of colors they are so well-known for, created by silica spheres. Depending on the place of origin and color of the main body, opalscan be differentiated fromDark or Black Opal, White or Light Opal, Milk or Crystal Opal, Boulder Opal, Opal Matrix, and also Mexicanand Fire Opal. Opal variations are unlimited.

Most opals come from Australian mines. They are also mined in Mexico, Brazil, Ethiopia, West Africa, and some U.S. states, such as Idaho and Nevada. Opals are softer stones, and have a hardness of 5.5 - 6 on the Mohs' Scale of Hardness.

Opals can be up to 10% water and are quite fragile. They should not be allowed to dry out or be exposed to sudden changes in temperature. Many types of opals are enhanced by infusion of colorless oils and resins to improve durability and color. Doublets and Triplets use a thin layerof opal glued to a black base. Use a soft damp cloth to clean opals.

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Pearl

pearl

Traditional birthstone for June

Since natural pearls are very rare, cultured pearls are the most common form of pearls on the market. A cultured pearl is created by seeding a live oyster or clam with a tiny shell bead, which the oyster gradually coats with layers of nacre, a substance produced by the oyster. Pearls are generally white, but are also available in a variety of natural tints, including cream, gray, pink, orange and violet. The most highly-valued shape is round, but they are available in a variety of shapes.

Saltwater pearls are produced by a saltwater mollusk in salt water. Any pearls cultured in this manner are considered saltwater pearls. The three most common are Akoya, Tahitian and South Sea Pearls. Saltwater cultured pearls are usually rounder than freshwater cultured pearls.

Akoya pearls are used in most jewelry today. They come from the Akoya oyster and are farmed in China and Japan. They are usually white or cream colored. Most Akoya pearls are on average larger than freshwater pearls.

South Sea pearls are among the largest pearls in the world. They are farmed on the northern coast of Australia and southern coast of China. South Sea pearls also have a subtle array of colors; they are usually white, but can also be found in silver or gold, which are rare among other pearl types.

Pearls are unique because of their natural dark colors. They come in several dark colors such as silver, charcoal, or a multitude of colors with the dominant color being green. They also come in black but they are extremely rare.

Pearls are cultured in Japan, Persian Gulf, China, Australia, Tahiti and the U.S. They are very soft, with a hardness of2.5 - 4.5 on the Mohs' Scale of Hardness.

Pearls are often bleached, dyed or irradiated. Because pearls are very fragile, they should be stored separately from other jewelry. They can be cleaned with a warm damp cloth and soapy water. Ultrasonic and steam cleaners should not be used. Pearl strands should periodically be re-strung.

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Peridot

peridot

Traditional birthstone for August

Peridot is a transparent lime or olive green member of the olivine family. Peridots are one of the few gemstones which come in one color. The intensity of the color depends on the amount of iron present in the stone. The color itself can vary over all shades of yellowish green and olive to a brownish green.

Peridots can be found in Pakistan and Afghanistan. They are also found in Burma, China, U.S., Africa, South America, and Australia. Peridots have a hardness of 6.5 - 7 on the Mohs' Scale of Hardness.

Peridots can be cleaned with warm soapy water and a soft brush. Ultrasonic cleaners should not be used.

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Ruby

ruby

Traditional birthstone for July

Rubies belong to the corundum family, and are actually red sapphires. Rubies come in a variety of shades, from a light, pale pinkish-red, to a dark purplish-red, to warm rich cranberry hues. Since it is common for rubies to have visible cracks and inclusions, most rubies available on the market today are treated to improve their clarity. Treatments can include heat or glass fill. Used solely to preserve their natural beauty, these treatments do not affect the authenticity of the gemstone.

Some of the finest rubies are mined in Myanmar (Burma), and are a unique color known as "pigeon's blood- red". Ruby deposits can also be found in Vietnam, Thailand, Northern Pakistan, Laos, Nepal, Afghanistan, East Africa, and India. Rubies have a hardness of 9 on the Mohs' Scale of Hardness.

Because of their durability, rubies can be cleaned with steamers or ultrasonic cleaners.

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Sapphire

sapphire

Traditional birthstone for September

Sapphire is also part of corundum family. Sapphires come in every color, including yellow, pink, orange, green and purple. Blue is often associated with sapphires and is one of most common colors on the market. Sapphires are most often heat treated to improve their color and clarity. A common industry practice, treated sapphires are viewed as authentic sapphires.

Sapphires are found in India, Burma, Ceylon, Thailand, Vietnam, Australia, Brazil and Africa. They have also been discovered in Madagascar and Brazil. Sapphires have a hardness of 9 on the Mohs' Scale of Hardness.

Because of their durability, sapphires can be cleaned with steamers or ultrasonic cleaners.

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Tanzanite

tanzanite

Modern birthstone for December

Tanzanites belong to the zoisite family, and are known for their incredible bluish-purple color. Since most tanzanite occurs as a golden brown stone, they are heat-treated to bring out the vivid violet blue. A common practice in the jewelry industry, the tanzanites can then range anywhere from a light lilac to dark saturated bluish-purple. Treated tanzanites are viewed as authentic.

Tanzanite's can only be found in the East African state of Tanzania. They have a hardness of 6 - 7 on the Mohs' Scale of Hardness.

Considered a relatively soft stone, it should only be cleaned with warm soapy water and a soft brush.

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Topaz

topaz

Blue Topaz - Modern birthstone for December
Yellow Topaz - Traditional birthstone for November

Topaz comes in a stunning variety of colors, the most common and popular being the Blue Topaz. Most blue topaz is treated by irradiation or by being heated to create a vibrant vivacious blue. Topaz is also treated to create many other colors. It is also available in a distinctive combination of colors known as "Mystic Topaz".

The gem is found all over the world, including Brazil, Afghanistan, Australia, China, Nigeria, Russia, Zimbabwe, Sri Lanka and the United States. Topaz has a hardness of 8 on the Mohs' Scale of Hardness.

Topaz can be cleaned with warm soapy water and a soft brush. Certain colors and treatments should not be cleaned with steam or ultrasonic cleaners.

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Tourmaline

tourmaline

Traditional birthstone for October

Tourmaline can exhibit two or more colors in one gem, and are available in a wide variety of colors, the most common being blue, green and pink. It can also be colorless. It is an industry standard for most tourmalines to be heat treated or irradiated to improve color and stability. These treatments do not affect the authenticity of the stones.

Tourmalines are found in major deposits in Brazil, Sri Lanka andSouth and Southwest Africa. They are also found in the U.S., Madagascar, Pakistan, and Afghanistan.Tourmalines have a hardness of 7-7.5 on the Mohs' Scale of Hardness.

Tourmaline can be cleaned with warm soapy water and soft brush. Ultrasonic cleaners should not be used.

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Turquoise

turquoise

Traditional birthstone for December

Turquoise can vary in color from pale blue to sky-blue to medium green, most commonly with a matrix (veining) of shades of brown to black. To enhance color, luster and improve stabilization, turquoise is often impregnated with wax or resin. To improve the beauty of the stone, other standard industry treatments include oiling and dyeing.

Turquoise is mined in China, Mexico, Israel, and Iran. It is also found in Arizona and Nevada. Turquoise has a hardness of 5 - 6 on Mohs' Scale of Hardness.

Turquoise can be cleaned with water and a soft brush. Avoid hot water and chemicals. Ultrasonic cleaners and steamers should not be used.

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Traditional and Modern Birthstones

MonthTraditional BirthstoneModern Birthstone
JanuaryGarnetGarnet
FebruaryAmethystAmethyst
MarchAquamarineAquamarine
AprilDiamondDiamond
MayEmeraldEmerald
JuneAlexandritePearl, Moonstone
JulyRubyRuby
AugustSardonyxPeridot
SeptemberSapphireSapphire
OctoberTourmalineTourmaline, Opal
NovemberCitrine, Yellow TopazCitrine
DecemberTurquoise, Lapis Lazuli, ZirconBlue Topaz, Turquoise, Tanzanite