This natural Brown Cassiterite originates from Australia and its weight is about 5 carats. The measurements are 9.86mm x 6.05mm x 4.06mm (length x width x depth). The shape/cut-style of this Cassiterite is Octagon Facet. This 4.5ct Cassiterite gem is available to order and can be shipped anywhere in the world. Gemstone Certification can also be provided as an optional service.
Cassiterite is a tin oxide mineral, and is the primary ore for tin. In addition to its important industrial use, it has some interesting properties that make high quality crystals valuable as gemstones. Cassiterite is reasonably hard, with a rating on the Mohs scale of 6 to 7. It tends to be opaque though thin crystals can be translucent. Its chief virtue is its multiple crystal faces and outstanding luster. Many specimens are graded as having "adamantine" (diamond-like) or submetallic luster.
Cassiterite is one of the densest gem materials known. It also has a very high refractive index, higher than zircon, sphene and demantoid garnet.
I have known about GemSelect for a while but this is my first purchase because I am a jewelry maker in the market for lower-priced gems that I can resell in jewelry. It's difficult to make much of a profit on cheaper jewelry when the shipping price is sometimes half of the total cost of the stone. I would make more purchases if I was in the market for a lot of higher-priced gems, but for now it will be just every once in a while that I shop here.
That being said, I think that the prices for gems are fair and I will continue shopping with GemSelect for my higher-priced gems that I make for myself or for orders that want specific gems that I can only find here.