Cassiterite, nicknamed tinstone, was the primary ore of Tin throughout early history and remains so today. Aside from its commercial value, it is used minimally in the gem/jewelry trade, but more so as collector specimens. It is typically black to brown in color, including reddish-black and reddish brown, and occasionally yellow, gray or white. Its crystals display an aesthetic sub-metallic luster. These dark, lustrous crystals on lighter matrix are of particular interest to collectors, and are commonly paired with Quartz, Muscovite, Pyrite, Fluorite and Albite to name a few.

The crystal system for Cassiterite is tetragonal, forming short prismatic, complex pyramidal, bipyramidal and dipyramidal crystals. Other forms include granular (course to fine), botryoidal and massive. It is also quite common for twinning and striations to occur.

Cassiterite is a very common mineral found throughout the world. Notable locations for quality crystal specimens include Australia, Bolivia, China, Czech Republic, England and Spain.