What is Cassiterite?

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The name Cassiterite is derived from the Greek “kassiteros”, meaning tin. Cassiterite (tin oxide, SnO2) is the best-known and principle tin ore. Tin (cassiterite) is currently classified as a conflict mineral along with tantalum (coltan), tungsten (wolramite) and gold. These 3T minerals, not including gold, are often found together in the same mineral deposits.

Cassiterite has been mined throughout ancient history and remains the most important source of tin today. The first alloy, used on a large scale since 3000 BC, was bronze, an alloy of tin and copper. After 600 BC, pure metallic tin was produced. Pewter, which is an alloy of 85–90% tin with the remainder commonly consisting of copper, antimony and lead, was used for flatware from the Bronze Age until the 20th century. In modern times, tin is used in many alloys, most notably tin/lead soft solders, which are typically 60% or more tin. Another large application for tin is corrosion-resistant tin plating of steel. Because of its low toxicity, tin-plated metal is commonly used for food packaging as tin cans, which are made mostly of steel.

Many of the commercial Cassiterite deposits exist in placer stream deposits where this very heavy mineral collects as rounded water-worn pebbles. Cassiterite is an economically important mineral, being the primary ore of the metal tin. It is also used as a collectors mineral with the transparent forms being highly desired.