Cassiterite is SnO2 or Tin oxide mineral. It is generally opaque but it is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite has been the chief ore of tin throughout in the past and remains the most important source of tin today.

Cassiterite is the most important ore of tin and is marked with high durability. The name of this mineral is derived from the word “Cassiterides” which was the word used to describe British islands in pre-Roman times. Their most prevalent usage is as gemstones. The name Cassiterite was derived from a Greek word “kassiteros” which stands for tin. It is also popularly known as ‘tinstones’.

Cassiterite occurs in pegmatites and can be washed into alluvial deposits. Localities include the Malay Peninsula, England, Germany, Australia, Bolivia, Mexico and Namibia.

Cassiterite is a rare natural gemstone. Its color can be black, brownish black, brown, gray, yellowish, greenish, red or even colorless. It has a hardness of 6 to 7 on the Moh’s scales. Cassiterite has much more dispersive fire than even diamond. It is one of the rarest gemstones.

Cassiterite is primarily concentrated in alluvial surfaces. They are mainly available in the tin mines located in Bolivia where they exist in hydrothermal veins. This type of ore is available in small elements that are derived from igneous rocks.

The different aspects of this ore are elaborately arranged and exhibit tremendous amount of luster. Associated minerals with which cassiterite ores are generally found are Tourmalines, Molybdenite, Bismuthinite, Topaz, Fluorite, and Wolframite.