Common Gemstone Terms
Gemstone: is a mineral or other natural material that is beautiful enough, durable enough, and rare enough, to be used for personal adornment or for the embellishment of personal possessions. This is the modern definition of a gemstone. Non-mineral gemstones include: coral, pearl, amber, ivory, these examples are all organic gemstones.
Natural: the term “natural” is placed before the name of a gemstone when there is a synthetic version of the stone available. The term gives no indication whether the gemstone has been treated or not, it simply indicates that the gemstone is of natural origin. Examples: – Natural Pink Sapphire (ie a synthetic is available), Synthetic Pink Sapphire (indicates it is not natural), Demantoid Garnet (no synthetic is produced so the term natural is not used).
Treated: Gemstones can undergo various treatments to enhance their value. These gemstones are still natural gemstones. Example: Natural Blue Sapphire – heat treated, Natural Emerald – oiled.
Synthetic: A synthetic ‘gemstone’ is a man-made material having the same chemical composition, crystal structure, and most physical properties of a (natural) gemstone. For example, Synthetic Ruby or Synthetic Diamond. Synthetic gemstones are sometimes called “lab-created”, “created” or “man-made”.
Imitation: Imitation gemstones are predominantly human-manufactured products that only visually resemble the gemstone they are intended to imitate. Examples: glass and composite stones (which are made from several components), have been used to ‘imitate’ gemstones. A gemstone can also be an imitation of another more valuable gemstone, e.g. a Blue Topaz may imitate an Aquamarine, or a Rubellite Tourmaline may imitate a Natural Ruby, and they are all natural gemstones. Imitation gemstones are sometimes called simulants.
Some Popular Gemstones
Amethyst: A member of the Quartz family. Colour ranges from pale lilac to deep purple. The major source of amethyst gemstones is Brazil. Others include India, Namibia, Sri Lanka, USA, Uruguay and Zambia. The hardness of amethyst is 7 on the Mohs scale, with Diamond being 10. Amethyst is the birthstone for February.
Aquamarine: A member of the Beryl family. Colour varies from greenish blues to blue-green. The major source of Aquamarine is Brazil. Other sources include Australia, China, Kenya, Madagascar & Nigeria. The hardness of aquamarine is 7.5 – 8 on the Mohs scale, with Diamond being 10. Aquamarine is the birthstone for March.
Citrine: A member of the Quartz family. Colour varies from yellow to orange. Sources of Citrine include Bolivia, Brazil and Spain. The hardness of Citrine is 7 on the Mohs scale, with Diamond being 10.Citrinte is one of the birthstones for November.
Emerald: A member of the Beryl family of gemstones. Colour is various shades of green. Sources of Emerald include Afghanistan, Brazil, Colombia, Pakistan, Russia, Zambia & Zimbabwe. The hardness of Emerald is 7.5 – 8 on the Mohs scale, with Diamond being 10. Emerald is the birthstone for May.
Peridot: Colour ranges from brownish green, yellowish green to greenish yellow. Sources of Peridot are Myanmar, Pakistan and USA. The hardness of Peridot is 6.5 – 7 on the Mohs scale, with Diamond being 10. Peridot is one of the birthstones for August.
Rhodolite: A member of the Garnet family. Colours range from light to dark purplish red through to reddish purple. Sources of Rhodolite include Sri Lanka, Tanzania and Zimbabwe. The hardness of Rhodolite is 7 – 7.5 on the Mohs scale, with Diamond being 10. Rhodolite, being garnet, is the birthstone for January.
Ruby: A member of the Corundum family. Colour is predominantly red but can be ever so slightly pink, purple or orange. Sources include Myanmar, Sri Lanka, Thailand, Afghanistan, Kenya, Madagascar and Vietnam. The hardness of Ruby is 9 on the Mohs scale, with Diamond being 10. Ruby is the birthstone for July.
Sapphire: A member of the Corundum family. Essentially Sapphire & Ruby are the same thing but differ only in colour. All corundum other than red is called sapphire. Popular colours are pink, blue and colourless but can be black, brown, violet and other colours. Sources include Australia, China, Kashmir, Madagascar, Burma, Sri Lanka, Thailand amont others. The hardness of Sapphire is 9 on the Mohs scale, with Diamond being 10. Sapphire is the birthstone for September.
Tanzanite: Colour is blue or light to dark violet-blue and blue-purple. Source is Tanzania. The hardness of Tanzanite is 6 – 7 on the Mohs scale, with Diamond being 10.
Topaz: Colours include brown, blue, green, yellow, orange, pink, red, purple or colourless. Sources of Topaz include Australia, Brazil, Madagascar, Mexico, Myanmar and Namibia. The hardness of Topaz is 8 on the Mohs scale, with Diamond being 10. Topaz is one of the birthstones for November.
Tourmaline: It occurs in almost any colour. The major source is Brazil but others include Afghanistan, Kenya, Burma, Pakistan, Russian and United States. The hardness of Tourmaline is 7 – 7.5 on the Mohs scale, with Diamond being 10.
Tsavorite: A member of the Garnet Family. Colours range from light to dark intense yellowish-green or green. Sources are Kenya and Tanzania. The hardness of Tsavorite is 7 – 7.5 on the Mohs scale, with Diamond being 10. Tsavorite, being garnet, is the birthstone for January.
Zircon: Colours include blue, greenish-blue, green, yellow, orange, red, brown purple. Sources include Australia, Cambodia, Sri Lanka, Thailand and Vietnam. The hardness of Zircon is 6 – 7.5 on the Mohs scale, with Diamond being 10.