Cassiterite

Formula: SnO2

Colour: Black, yellow, brown, red or white.

Lustre: Adamantine, Greasy, Sub-Metallic

Hardness: 6 – 7

Specific Gravity: 6.98 – 7.01

Crystal System: Tetragonal

Member of: Rutile Group

Name: The mineral name is derived from the term “Cassiterides” which was applied ‘islands off the western coast of Europe’ in pre-Roman times (the exact location of these ‘islands’ has been hotly debated over the years, current thought is that the source was probably mainland Spain and that even 2000 years ago, traders had a habit of providing misleading locality information to protect their sources).

Isostructural with: Rutile

The primary ore of Tin, this mineral is found in hydrothermal veins and pegmatites associated with granite intrusions. Because of its durability, it is also frequently found concentrated in alluvial placer deposits, sometimes in large enough quantities to be commercially exploitable, as in Malaysia, for example.