Cassiterite
Phenomenal & Rare Gems
Cassiterite is tin oxide, SnO₂, and the principal ore of tin. Most crystals are dark and nearly opaque, but pale thin crystals can be translucent; its high refractive index and dispersion give suitable transparent material strong brilliance.
Identity
- Material or variety
- Cassiterite
- Scientific or material identity
- Cassiterite
- Classification
- Natural mineral or mineral variety
- Aliases or trade names
- Tinstone · Wood tin
- Composition or formula
- SnO₂
- Crystal system or structure
- Tetragonal
- Geological or manufacturing origin
- Can form in more than one geological environment, or combines several materials.
- Mohs hardness
- 6 to 7
Origins
Bolivia · Myanmar · Namibia · Sri Lanka · USA
Appearance & optical properties
dark reddish-brown cassiterite with glassy luster.
History & discovery
Cassiterite supplied most tin through ancient history and remains the metal’s most important ore. Its name is linked to Greek kassiteros, meaning tin; rounded or banded aggregates have long been called wood tin.
Uses & care
- Common uses
- Cassiterite is mined chiefly for tin. Transparent crystals are occasionally faceted as collector gems, and well-formed twins are prized as mineral specimens.
- Handling and cleaning
- Handle faceted stones and crystals carefully despite their hardness: cassiterite can be brittle. Clean with warm soapy water and a soft brush, avoiding impacts, steam and ultrasonic cleaning.
Jewellery
5 pieces of Cassiterite jewellery. Learners earn each one in DigMyGem by learning words; until then it shows as a silhouette.
Tin Vein Ring
Ring
A dark cassiterite stone with near diamond fire sits in a ring shaped to look like a seam of tin ore.
Cornwall Cassiterite Brooch
Brooch
A cluster of cassiterite crystals from the old tin mines is mounted like a dark bouquet on bronze.
Erzgebirge Pendant
Pendant
A twin crystal of cassiterite hangs from a silver loop, named for the ore mountains where it was found.
Tin Lustre Earrings
Earrings
An imagined pair of earrings set with cassiterite, the tin ore, cut to show its hard glassy shine in honey brown.
Tinner's Crown
Crown
An imagined silver crown set with faceted cassiterite, the tin ore, in honour of the tin miners.