Cassiterite, nicknamed "the tin stone”, is an fairly common oxide, which is noted for historically being the most important ore for the extraction of tin. In fact, the mineral’s name is actually derived from a Greek word for the metal, kassiteros. Tin was especially important in the ancient world, as it is used in combination with copper to produce bronze.

Due to its very high physical (SG = 6.7-7.1) and optical (RI = 2.0-2.1) density, cassiterite is able to display flashes of spectral “fire” to an even greater extent than diamond. In addition, the polished material possesses a diamond-like adamantine luster. However, while cassiterite can occur in a wide range of hues, gem-quality reddish, greenish, brownish and/or yellowish crystals tend to be far more rare than the less desirable, overly dark material.