Gemstones: The Jewelry Grade Mineral Varieties.
DSO Archive publishes a research on some of the jewelry grade gemstones. The study observes their mineral formation, the trace elements that contaminate them and the varieties produced. Ethical sourcing involves all types of gemstones and international trading regulations must be observed by miners, traders, cutters and retailers.
The mineral Carbon is able to generate many allotropes, structural variations of the same elements, including Diamonds, Graphite, Lonsdaleite, Amorphous Carbon, Nanocarbons and Glassy Carbon.
A Diamond is a metastable allotrope of carbon known as crystal lattice. The Color ranges from clear transparent white to yellow. Color variations may naturally occur and it includes all the hues and combinations of Brown, Yellow, Orange, Red, Purple, Violet, Pink, Blue, Green, Grey and Black.
The Beryl mineral is a beryllium aluminium cyclosilicate and it includes Aquamarine, Emerald, Goshenite, Heliodor, Morganite and Red Beryl. Uncontaminated beryl is colorless, but it is frequently colored by impurities producing color variations including blue, green, yellow, red and white.
The Aquamarine is a blue variety of the mineral Beryl that contains traces of iron which affect its color causing it to range from a very light blue to a richly saturated blue.
Brazil has the largest deposits of Aquamarine which is also mined in Angola, Kenya, Madagascar, Malawi, Mozambique, Nigeria, Pakistan, Russia, Sri Lanka, Tanzania, USA and Zambia.
The Emerald is a green variety of the mineral Beryl that contains traces of either chromium or vanadium that cause the green coloring.
Colombia is the world’s largest producer by Volume counting for well over half of the global output and together with Brazil and Zambia represents most of the global production. Pipes of Emeralds are mined all over the world including in Afghanistan, Australia, Cambodia, Canada, China, Egypt, Ethiopia, India, Kazakhstan, Madagascar, Mozambique, Namibia, Nigeria, Norway, Pakistan, Russia, Somalia, South Africa, Tanzania, United States, Zimbabwe and across Europe.
Colombia produces also amongst the finest Emeralds with light inclusions compared to the Brazilian gemstones that have darker colored inclusions. The Emeralds from Zambia may have blue and grey color presence in the green.
The Corundum mineral is a crystalline form of aluminium oxide typically containing traces of iron, titanium, vanadium and chromium. It is the second hardest mineral in nature after diamonds and it includes Ruby and its variation Star Ruby, Emery, Sapphire and its varieties Padparadschah and Star Sapphire.
The Sapphire is a variety of the mineral Corundum that has trace elements of either iron, titanium, chromium, vanadium, or magnesium. Sapphires occur in blue or fancy yellow, purple, orange, and green.
The Orange-Pink variety of Corundum called Sapphire Padparadschah is rare and much sought after. A blue variation of the Corundum mineral presents asterism with a six-points star and it is named Star Sapphire.
Sapphires are mined in Australia, Cambodia, Cameroon, China, Colombia, Ethiopia, India, Kenya, Laos, Madagascar, Malawi, Mozambique, Myanmar, Nigeria, Rwanda, Sri Lanka, Tanzania, Thailand, United States and Vietnam.
With slight differences occurring from mine to mine, the finest Sapphires are perceived to be those unearthed in Kashmir, India. Highly praised are also the Sapphires extracted in Myanmar (Burma), Sri Lanka and Madagascar.
The Ruby is a variety of the mineral Corundum that has trace elements of chromium. Rubies occur in Pink and Red ranging from deep to highly saturated hues. A variety of this mineral presents asterism and it is named Star Ruby.
Rubies are mined in Afghanistan, Australia, Brazil, Colombia, India, Japan, Macedonia, Madagascar, Namibia, Nepal, Pakistan, Scotland, Tajikistan, Tanzania, Thailand and Vietnam.
Historically, the Rubies from Burma (Myanmar) are highly praised for their parameters and color. Important deposits have more recently been located in Afghanistan and Pakistan. The region of Kashmir produces high grade Rubies alongside other gemstones.
The Tanzanite is a recently discovered variety of the Zoisite, a calcium aluminium hydroxy sorosilicate with traces of vanadium that cause the blue to violet color of the mineral.
Pipes of Tanzanite, as baptised by Tiffany & Co., have only been located in Tanzania; the mineral is extracted in the Arusha region of the African country.
The Opal is a mineraloid as it does not present a crystal formation, it is an hydrated amorphous form of silica. It may be transparent, translucent or solid and it occurs in a variety of colors including colorless, white, brown, yellow, orange, purple, red, blue, green, gray and the rarest of all black.
Opal has numerous variations like Boulder Opal, Fire Opal, Hungarian Opal and Lemon Opal. Precious Opal’s color peculiarity is that different colors may appear depending on the viewing angles and the light reflection and refraction. This is referred to as play-of-color; it is the optical result of the internal structure, the composition and the light reflection.
Opals are mined in Australia, US and Mexico primarily. Important deposits include Brazil, Eastern Europe and Honduras.
The Tourmaline is a crystalline boron silicate mineral with traces of aluminium, iron, magnesium, sodium, lithium, or potassium. The mineral variations include Schorl, Dravite and Elbaite with its Rubellite, Verdelite, Indicolite, Watermelon Tourmaline, Chrome Tourmaline, Paraiba and Achroite varieties.
The Paraiba Tourmaline, discovered in the homonymous Brazilian state from which it was named, is found in Brazil, Nigeria and Mozambique. The rare neon-blue Paraiba from Brazil is the most praised variance of this mineral.
The Quartz is a mineral with crystal formation made up of atoms of silicon and oxygen that when contaminated by various impurities produce a wide range of colors. The family of Quartz includes the purple Amethyst, the yellow, orange and red Citrine, the Smoky Quartz, the Rose Quartz, the transparent Rock Crystal, the Milky Quartz, the golden Rutilated Quartz, the Ametrine, the green Prasiolite, Blue Quartz, Tourmalinated Quartz and Cat’s Eye Quartz.