ShreeNath Gems

The Mohs Scale of Hardness

The Moh's scale was devised in 1812 by Austrian mineralogist, Friedrich Moh, to measure a mineral's hardness and it's resistance to scratching. The scale goes from talc as number 1, being the softest, to diamonds as number 10, being the hardest substance known.

BIRTHSTONES

Emerald (Beryl)

Hardness : 7.5 - 8.0.
Occurrence : Colombia, Brazil, Zimbabwe (Rhodesia), South Africa, Ural mountains (Russia), Zambia, India, Tanzania, Pakistan, Australia, U.S. (Connecticut, Maine, North Carolina), Austria and Norway.
Appearance
Emerald refers to the green variety of beryl. There are however, gem quality green beryls which are not emeralds. All emeralds contain inclusions, which are evidence as to the genuineness of the stone. The name is derived from the Greek word Smaragdos, meaning "green stone". Emerald is the birthstone of the month of May.
Enhancements
Emerald is usually treated with colorless oil, wax, or natural and synthetic resins into voids to improve appearance. Surface cavities of emerald is commonly filled with a hardened colorless substance. Emerald is also occasionally dyed with dye or colored oil.

Garnet

Hardness : 7.0 - 7.5.
Occurrence : U.S. (Arizona), South Africa, Argentina, Australia, Brazil, Myanmar (Burma), Scotland, Switzerland, Tanzania
Appearance
Garnet is the name which can be applied to six similar mineral species, namely almandine, pyrope, spessartine, grossular, andradite and uvarovite. To further complicate matters, many garnets are actually a combination of these minerals. Rhodolite garnet for instance, is a combination of almandine and pyrope, and is sometimes referred to as pyrope-almandine garnet. There are also many trade names and other commonly used names which only adds to the confusion, such as Rhodolite, Tsavorite, Hessonite, Malaya, Mozambique, Mandarin, Ant-hill, Leuco, Hydrogrossular, Demantoid, Melanite, Topazolite, Thai. Other names such as "cape ruby" are simply misleading and deceptive. Some garnets also exhibit color change and stars.
Enhancements
Garnet in general is not enhanced.

Gold Included Quartz

Hardness : 7.0.
Occurrence : Worldwide, found in gold deposits.
Appearance
Metallic gold, included in white milky quartz.
Enhancements
Gold included quartz is not enhanced.

Grossular Garnet

Hardness : 7.0 - 7.5.
Occurrence : Sri Lanka, Canada, Pakistan, South Africa, Tanzania, Russia and the U.S.. This is a fairly rare garnet.
Appearance
Cinnamon orange (hessonite), pink and emerald green (tsavorite garnet).
Enhancements
Grossular garnet is not enhanced.

Mexican Fire Opal

Hardness : 5.5 - 6.5.
Occurrence : Australia, former Czechoslovakia, U.S., Brazil, Mexico and southern Africa. Opal and tourmaline are the birthstones of the month of October.
Appearance
Orangish yellow to dark red. The reddish fire opal is sometimes called "cherry opal".
Enhancements
Mexican fire opal is not enhanced.

Peridot

Hardness : 6.5 - 7.0.
Occurrence : St. John's Island, Zebirget Island, Red Sea (Egypt), Norway, Eifel, Germany, San Carlos (Arizona), Hawaii, Myanmar (Burma), and Italy.
Appearance
Olive green to yellowish green. The darker green is known as peridot, the yellower type chrysolite. Peridot and sardonyx are the birthstones of the month of August.
Enhancements
Peridot is rarely treated with colorless oil, wax, natural and synthetic unhardened resins into voids to improve appearance. Surface fractures are rarely filled with a colorless hardened substance.

Peruvian Blue Opal

Hardness : 5.5 - 6.5.
Occurrence : Peru
Appearance
Translucent, and similar in color to turquoise in color.
Enhancements
Peruvian blue opal is not enhanced.

Pink Sapphire

Hardness : 9.0.
Occurrence : Myanmar (Burma), Thailand, India, Sri Lanka (Ceylon), Tanzania, Afghanistan, Australia, Brazil, Cambodia, Malagasy Republic, Malawi, Pakistan, Zimbabwe (Rhodesia), United States (Montana, North Carolina).
Appearance
Lighter in color than ruby, these gemstones are referred to as pink sapphire. The term ruby refers to the darker red corundum colored by Chromium impurities.
Enhancements
Pink sapphire is always heat treated to produce, intensify or lighten color and/or improve color uniformity and appearance.

Pink Tourmaline

Hardness : 7.0.
Occurrence : Madagascar, North America, Brazil, Myanmar (Burma), Africa, Siberia, Australia, Sri Lanka (Ceylon). Tourmaline and opal are the birthstones of the month of October. Tourmaline is the national gemstone of the United States.
Appearance
Pink to reddish in color.
Enhancements
Pink, red and purple tourmaline is occasionally heat treated to improve color.

Quartz

Hardness : 7.0
Occurrence : Worldwide. One of the most common minerals.
Appearance
Quartz can be found in a variety of colors, violet (amethyst), golden yellow (citrine), pink or peachish (rose quartz), brown (smoky quartz), green (prasiolite) and colorless (rock crystal). Quartz is sometimes found with inclusions of other minerals such as rutile (sagenite, or rutilated quartz) or tourmaline (tourmalinated quartz), making them look quite remarkable. Chalcedony, a micro-crystalline member of the quartz family consists of a number of stones, namely agate, dendritic agate, fire agate, bloodstone (heliotrope), plasma, chrysoprase, prase, fossilized wood, jasper, carnelian, moss agate, onyx, sardonyx, and sard
Enhancements
Clear quartz is not enhanced. Refer to specific pages on other types.

Rhodolite Garnet

Hardness : 7.0 - 7.5.
Occurrence : U.S., Zimbabwe, and Sri Lanka (Ceylon).
Appearance
Rhodolite garnet is a combination of almandine and pyrope, and is sometimes referred to as pyrope-almandine garnet. The name is derived from the Greek words rhodon and lithos, meaning rose-stone. Raspberry red to a deep pinkish-red. Garnet is the birthstone of the month of January.
Enhancements
Rhodolite garnet is not enhanced.

Pink Amethyst

Hardness : 7.0.
Occurrence : Worldwide
Appearance
Also known as lavender amethyst, and is much lighter in color than amethyst.
Enhancements
Occasionally heated to lighten color and/or to remove "smoky" components.

Rose Quartz

Hardness : 7.0
Occurrence : Madagascar, Brazil, U.S. (Colorado), former USSR, Scotland and Spain.
Appearance
The soft pink variety of quartz, generally cloudy, or milky in appearance due to minute inclusions of foreign substances. It's somewhat more rare than other varieties of quartz.
Enhancements
Rose quartz is not enhanced.

Rubellite (Tourmaline)

Hardness : 7.0
Occurrence : Madagascar, North America, Brazil, Myanmar (Burma), Africa, Siberia, Australia, Sri Lanka (Ceylon). Tourmaline and opal are the birthstones of the month of October. Tourmaline is the national gemstone of the United States.
Appearance
The reddish to purple color of tourmaline is called rubellite. Like emerald, inclusions are common. Ruby red colored stones are the most valuable.
Enhancements
Pink, red and purple tourmaline is occasionally heat treated to improve color.

Ruby (Corundum)

Hardness : 9.0.
Occurrence : Myanmar (Burma), Thailand, India, Sri Lanka (Ceylon), Tanzania, Afghanistan, Australia, Brazil, Cambodia, Malagasy Republic, Malawi, Pakistan, Zimbabwe (Rhodesia), United States (Montana, North Carolina).
Appearance
Named for it's color (Latin Rubeus). Ruby has been confused with red spinel and garnet. The color can range from "pigeon-blood" to brownish. Other colors are known as sapphire. Inclusions are common, and are used to tell the difference between a synthetic and natural stone. Ruby is the birthstone of the month of July.
Enhancements
Ruby is usually heat treated to improve color and appearance. Surface cavities and fractures are commonly filled with a foreign material, including glass. As a by-product of heat treatment, the presence of solidified borax or similar colorless substances which are visible under 10x magnification are common.

Rutilated Quartz

Hardness : 7.0
Occurrence : Worldwide.
Appearance
Sometimes called "sagenite", quartz crystals which are included with "needle like" rutile crystals are common and are quite attractive. Other common attractive inclusions found are tourmaline, gold, silver, pyrite and goethite.
Enhancements
Rutilated quartz is not enhanced.

Sapphire (Corundum)

Hardness : 9.0
Occurrence : Myanmar (Burma), Thailand, India, Sri Lanka (Ceylon), Tanzania, Afghanistan, Australia, Brazil, Cambodia, Malagasy Republic, Malawi, Pakistan, Zimbabwe (Rhodesia), United States (Montana, North Carolina).
Appearance
Sapphires are found in a variety of colors. The reddish colors are called ruby. People generally think of sapphires as blue in color, although they are also colorless, pink, orange, green, golden, yellow, purple and black. Sapphire is the birthstone of the month of September. Red sapphires are known as ruby, and pinkish orange sapphire as padparadscha.
Enhancements
Sapphire is always heat treated to produce, intensify or lighten color and/or improve color uniformity and appearance. Heat treatment of sapphires is performed at the sapphire mines, and is a industry-wide accepted practice. We have had a lot of requests for untreated sapphires, but they don't exist. Unless you dig it out of the ground yourself, always assume that any sapphire is heat treated.

Smoky Quartz

Hardness : 7.0.
Occurrence : Brazil, Madagascar, Switzerland, U.S. (Colorado), Australia and Spain. Smoky quartz from the Cairngorm Mountains of Scotland is called cairngorm.
Appearance
Smoky quartz is the dark brown variety of quartz. In the past, these were often sold as "smoky topaz". There is no such gemstone known as smoky topaz and it's illegal to refer to quartz as "topaz". Watch out for some unscrupulous dealers who sell "smoky topaz", it is probably quartz. Citrine was often passed off as topaz as well. Smoky quartz crystals can form together with citrine crystals to form bi-colored quartz. Smoky quartz is sometimes found rutilated, which would be called Smoky Sagenite (Rutilated Quartz).
Enhancements
Smoky quartz is occasionally produced by irradiation of colorless quartz.

Tourmaline

Hardness : 7.0
Occurrence : Madagascar, North America, Brazil, Myanmar (Burma), Africa, Siberia, Australia, Sri Lanka (Ceylon). Tourmaline and opal are the birthstones of the month of October. Tourmaline is the national gemstone of the United States.
Appearance
There are more colors of tourmaline than any other known gemstone. The lighter colored stones are more valuable.
Enhancements
Refer to specific pages

Turquoise

Hardness : 7.0.
Occurrence : Turkey, Iran, Afghanistan, Eastern Australia, Tibet, Israel, Tanzania, Southwestern U.S.. Turquoise and zircon are the birthstones of the month of December.
Appearance
Sky blue to bluish green. The name means "Turkish stone". Turquoise is porous, so contact with liquids, oils or even perspiration should be avoided. Jewelry made with turquoise should be removed before washing hands, etc.. The pure blue color is rare, most stones contain the matrix from which it was found. Although the stones without matrix are rarer and more valuable, many people find the black matrix attractive, and makes the stone unique.
Enhancements
Turquoise is commonly impregnated with plastic, colorless oil or wax to improve color and increase durability. Untreated turquoise will eventually turn green.

Yellow Sapphire

Hardness : 9.0.
Occurrence : Myanmar (Burma), Thailand, India, Sri Lanka (Ceylon), Tanzania, Afghanistan, Australia, Brazil, Cambodia, Malagasy Republic, Malawi, Pakistan, Zimbabwe (Rhodesia), United States (Montana, North Carolina).
Appearance
Lacking orangish tones, these lemon yellow sapphires are really quite stunning. Can be confused with citrine.
Enhancements
Yellow sapphire is always heat treated to produce, intensify or lighten color and/or improve color uniformity and appearance. Yellow sapphire is occasionally irradiated to provide temporary intense yellow or orange color.

Quartz

Hardness : 7.0
Occurrence : Worldwide. One of the most common minerals.
Appearance
Quartz can be found in a variety of colors, violet (amethyst), golden yellow (citrine), pink or peachish (rose quartz), brown (smoky quartz), green (prasiolite) and colorless (rock crystal). Quartz is sometimes found with inclusions of other minerals such as rutile (sagenite, or rutilated quartz) or tourmaline (tourmalinated quartz), making them look quite remarkable. Chalcedony, a micro-crystalline member of the quartz family consists of a number of stones, namely agate, dendritic agate, fire agate, bloodstone (heliotrope), plasma, chrysoprase, prase, fossilized wood, jasper, carnelian, moss agate, onyx, sardonyx, and sard
Enhancements
Clear quartz is not enhanced. Refer to specific pages on other types.

Onyx

Hardness : 6.5 - 7.0.
Occurrence : Worldwide. A member of the family (micro-crystalline)
Appearance
Onyx is the name given to hich is uniform in color, generally black or white. Onyx should not be confused with onyx marble, a banded stone which is a form of limestone
Enhancements
Black and colored onyx is always dyed.

Lemon Quartz

Hardness : 7.0.
Occurrence : Brazil
Appearance
Yellow green in color,
Enhancements
Lmeon is usually produced by heating various types of Quartz

Iolite

Hardness : 7.0 - 7.5.
Occurrence : Named after P. Cordier, a French geologist. Cordierite is also known as iolite and dichroite. Other common names are water sapphire and Vikings' compass, named so because of it's ability to determine the direction of the sun on overcast days. Cordierite is found in Germany, Brazil, Norway, Finland and Madagascar.
Appearance
Has strong pleochroism, meaning the gemstone changes colors depending which angle it is viewed from. Cordierite displays colors ranging from deep blue, to violet and light blue and grayish blue.
Enhancements
Iolite is not enhanced.

Labradorite

Hardness : 6.0.
Occurrence : Labrador (Canada), Finland, Norway, former USSR
Appearance
Can be red, orange, yellow, colorless, with a bluish play of color, "schiller". Spectrolite is the name for the Finnish labradorite.
Enhancements
Labradorite is not known to be enhanced.