Cassiterite is a major ore of tin. In fact, it is the chief ore of tin and was one of the first metal alloys. Cassiterite's name actually derives from the Greek word for tin, kassiteros. The name has also been said to come from the Phoenician word Cassiterid, referring to the islands of Ireland and Britain, both ancient sources of tin. Cassiterite's importance as a tin ore has been known for millennia. Since 2000 BD, cassiterite mines have been worked. One of the oldest cassiterite mines is in Cornwall, England and is now completely exhausted of all minerals. Cassiterite was actually Britain's most important export. In fact, the Roman invasion of Britain was mostly caused by the Roman's desire to control Britain's cassiterite exports. During the Bronze Age, cassiterite was a major discovery used towards technological advancement, as it was used to form the alloy bronze. This was done by heating up cassiterite and adding it to molten copper.
Cassiterite is used as a source of tin and bronze, but is also valued as a beautiful gemstone. Rating a 6 to 7 on the hardness scale and having perfect cleavage and high density, cassiterite is very easy to cut. However, the stone needs a good polishing to become a beautiful gemstone suitable for faceting in jewelry. Cassiterite is usually found in small stones. Large cut stones of more than one carat are rare. Cassiterite is highly prized for its beautiful sparkle, which comes from its high adamantine luster. Its luster can also be sub-metallic and greasy. Cassiterite is usually an opaque stone, but can also be transparent and translucent when the crystals are thin. It is usually black, but can also be reddish brown, brown, brownish white, yellow, red, or colorless. Crystals may also have white or brownish streaks. Crystal twinning is common within the stone.
Cassiterite is usually found in or near granite masses, igneous rocks, or alluvial deposits. When it is found as rounded alluvial pebbles, cassiterite is called stream tin. It is usually found in association with fluorite, apatite, wolframite, arsenopyrite, bismuthinite, 
topaz, 
quartz, tourmaline, mica, and molybdenite. The stone is usually found as an eight sided prism which consisting of two four-sided prisms, one of which is dominant.
The most highly prized cassiterite comes from Erongo, in central Namibia, and Galicia, in Spain. High quality specimens have also been found in hydrothermal veins in the tin mines of Bolivia. Cassiterite can also be found in various locations around China, Indonesia, Malaysia, Mexico, Namibia, Russia, Thailand, and Spain. Cassiterite is a stone for those who desire greatness and perfection. It can aid the wearer in getting rid of hesitation, wasted energy and time, and regression, pushing the wearer towards growth. It has also been said to be extremely helpful for those who suffer from addiction.
