Cassiterite is a natural tin ore, a heavy black to brown crystal with a bright shine. We do not carry it. It is a collector's stone and no crystal guide we use has a profile of it.
Oxide
Cassiterite
Casiterita
- Palette
- Black Brown
- Mined in
- Bolivia, United Kingdom, Malaysia, Thailand, Indonesia, Russia, China, Namibia
- Hardness
- Mohs 6.0–7.0 ?
- See-through
- opaque
- Known since
- Prehistoric
- Named for
- Greek kassiteros, 'tin'
- Also sold as
- tin stone, tinstone, tin spar
- Intention
- Abundance
- Looking for
- Prosperity
- Water
- Keep it dry; wipe with a soft cloth
- Dye or finish
- We found no bead seller or reference that states anything done to cassiterite; it is mostly sold as natural crystals and rough.
Not in our pieces now
7× WATER
Cassiterite is about seven times as dense as water, which is why miners can wash the ore out of lighter gravel in streams.
10 ISOTOPES
Tin, the metal locked in cassiterite, has 10 stable isotopes, more than any other element.
60°
Cassiterite crystals often twin into a bent 'elbow' shape, with the two parts meeting at nearly 60 degrees.
What it is
Tin oxide, the main ore of tin, in heavy black to brown crystals with a bright, almost metallic shine. It is about seven times as dense as water, so it feels very heavy in the hand. Pale, clear faceted stones exist but are scarce, and it is mostly a collector mineral.
Where it comes from
Bolivia is known for the finest cassiterite crystals, England's Cornwall mined it for about 4,500 years, and most tin today comes from stream deposits in Malaysia, Thailand and Indonesia.
In history
Cassiterite was the chief tin ore of the ancient world, and tin use dates to the start of the Bronze Age around 3000 BC. The tin workings of Cornwall and Devon in England are about 4,500 years old.
What's said about it
Its story is about trade rather than belief. It was the chief tin ore of the ancient world, mined in Cornwall for some 4,500 years, and its Greek name appears in Homer.
Collectors keep it as crystals on a shelf. If you like the dark, weighty look, black onyx and bronzite are the ones we carry.
How people wear or keep it: On a shelf or desk, in a display case, or in a pouch of its own.
In crystal practice
In the crystal tradition, cassiterite is paired with the root and solar plexus chakras, so practitioners rest it there during meditation or lie down with it in place for a few quiet minutes. Day to day, the same tradition suggests keeping it close: on a shelf or desk, in a display case, in a pouch of its own. People reach for it when they want prosperity, and many set an intention when they put it on. Most practitioners cleanse a new stone first (running water only if the stone can take it, otherwise smoke or moonlight) and set it aside now and then to rest.
These are beliefs people have held and still hold about the stone, reported as such. Nothing here is a promise or a medical claim. We sell stones as jewelry, not for these effects.
Associations
The chakra and star sign this stone is usually matched with. These are popular traditions, not facts about the stone.
ChakraRoot, Solar Plexus
ZodiacSagittarius
Also calledtin stone, tinstone, tin spar
Care
- It is Mohs 6 to 7 with only imperfect cleavage, so it is fairly tough, but it is very heavy and can pull on a thin setting.
- Most crystals are opaque and dark. Clean with a soft brush, mild soap and warm water, then dry.
- Stones with inclusions are best cleaned by hand only. Skip ultrasonic cleaners.
- Keep it in its own pouch so it does not scratch softer stones.
How to tell what you have
- Cassiterite is tin oxide: very heavy (about 7 times water), with a bright almost metallic shine, hardness 6 to 7 and a white to brownish streak. Elbow-shaped twins are common.
- Black heavy beads sold under this name could be hematite or glass, so check the weight: cassiterite feels much heavier than quartz or glass of the same size.
What sets the price
Price follows how clear and sparkly the stone is and its color, and fine clean crystals cost far more than dull or dark material.
Rules and sourcing
Cassiterite is tin ore, and tin is one of the minerals the US conflict-minerals rule asks reporting companies to trace back to its source, so a buyer can fairly ask where the beads came from.
Questions people ask at our table
What is cassiterite?
It is tin oxide, the main ore tin is smelted from. It forms black to brown crystals and is very dense.
Why does it feel so heavy?
Its density is roughly seven times that of water, which is high for a stone this size. That weight helps miners separate it from lighter rock.
Is it used in jewelry?
Only as a collector stone. Faceted cassiterite has strong fire, but clear rough is scarce and most crystals are dark and opaque.
Where is it from?
Bolivia is a famous source of crystals. England's Cornwall and Devon are old tin districts, and most modern production is in Malaysia, Thailand, Indonesia and Russia.
Is it a conflict mineral?
Tin ore from parts of eastern Congo is labeled that way. If you buy a specimen, ask where it was mined.
Not in our pieces right now
Stones we do carry that are close to it are listed under related stones.
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