simpsonite
Sign in to saveSimpsonite has a general formula of . It occurs as euhedral to subhedral tabular to short and prismatic crystals, commonly in subparallel groups. Under the petrographic microscope it has a very high relief.
Key facts
- Mineral.mohs
- 7–7.5
- Mineral.name
- Simpsonite
- Mineral.category
- Oxide minerals
- Mineral.image
- Simpsonite-154999.jpg
- Mineral.imagesize
- 300px
- Mineral.caption
- Locality: Alto do Giz pegmatite, Rio Grande do Norte, Brazil. Size: 1.6 × 1.5 × 1.8 cm.
- Mineral.IMAsymbol
- Spn
- Mineral.molweight
- 813.65 g/mol
- Mineral.strunz
- 4.DC.10
- Mineral.system
- Trigonal
- Mineral.class
- Pyramidal (3) H-M symbol: (3)
- Mineral.symmetry
- P3
- Mineral.unit cell
- a = 7.37, c = 4.51 [Å]; Z = 1
- Mineral.color
- White to cream, yellow to yellow-brown when altered
- Mineral.habit
- Euhedral, prismatic, striated
- Mineral.cleavage
- None
- Mineral.fracture
- Conchoidal
- Mineral.tenacity
- Brittle
via Wikipedia infobox
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Encyclopedic overview
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Simpsonite has a general formula of . It occurs as euhedral to subhedral tabular to short and prismatic crystals, commonly in subparallel groups. Under the petrographic microscope it has a very high relief.
Discovered in 1938, it was named after Edward Sydney Simpson (1875–1939), government mineralogist and analyst of Western Australia. It is an accessory mineral in some tantalum-rich granite pegmatites. It occurs in association with tantalite, manganotantalite, microlite, tapiolite, beryl, spodumene, montebrasite, pollucite, petalite, eucryptite, tourmaline, muscovite and quartz. It is found in a few locations around the world, notably in the Onca and Paraíba mines of Rio Grande do Norte, Brazil and at Tabba Tabba, Western Australia.
Excerpted from Wikipedia’s “simpsonite” article, available under the CC BY-SA 4.0 licence.