allactite
Sign in to saveAllactite is a rare arsenate mineral of metamorphosed manganese zinc ore deposits. It is found in Sweden and New Jersey, US. Its name originated from the Greek αλλάκτειν (allaktein) meaning "to change", referring to the strong pleochroism of the mineral.
Key facts
- Mineral.name
- Allactite
- Mineral.category
- Arsenate mineral
- Mineral.image
- Allactite-319883.jpg
- Mineral.imagesize
- 260px
- Mineral.caption
- Picture width 3 mm
- Mineral.formula
- Mn7(AsO4)2(OH)8
- Mineral.IMAsymbol
- Ala
- Mineral.strunz
- 8.BE.30
- Mineral.dana
- 41.2.1.1
- Mineral.system
- Monoclinic
- Mineral.class
- Prismatic (2/m) (same H-M symbol)
- Mineral.symmetry
- P21/a
- Mineral.unit cell
- a = 11.03, b = 12.12 c = 5.51 [Å], β = 114°, Z = 2
- Mineral.color
- Brown, dark to light purplish red, brownish red, colorless to white
- Mineral.habit
- Elongated prisms, bladed, tabular, rosette-like aggregates
- Mineral.cleavage
- Distinct, {001}
- Mineral.fracture
- Uneven
- Mineral.tenacity
- Brittle
via Wikipedia infobox
Wikidata facts
- Image
- Allactite-116056.jpg
Show 6 more facts
- Commons category
- Allactite
- Nickel-Strunz 9th edition (updated 2009)
- 8.BE.30
- Nickel-Strunz '10th ed', review of (9th ed/ 2009 update)
- 8.BE.30
- IMA Mineral Symbol
- Ala
- chemical formula
- Mn²⁺₇(AsO₄)₂(OH)₈
- Strunz 8th edition (series ID, updated)
- VII/B.10
Sources (1)
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{{Infobox mineral | name = Allactite | category = Arsenate mineral | image = Allactite-319883.jpg | imagesize = 260px | alt = | caption = Picture width 3 mm | formula = Mn7(AsO4)2(OH)8 |IMAsymbol=Ala | molweight = | strunz = 8.BE.30 | dana = 41.2.1.1 | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = P21/a | unit cell = a = 11.03, b = 12.12 c = 5.51 [Å], β = 114°, Z = 2 | color = Brown, dark to light purplish red, brownish red, colorless to white | habit = Elongated prisms, bladed, tabular, rosette-like aggregates | twinning = | cleavage = Distinct, {001} | fracture = Uneven | tenacity = Brittle | mohs = 4.5 | luster = Vitreous, slightly greasy on fracture surfaces | refractive = nα = 1.755–1.761 nβ = 1.772–1.786 nγ = 1.774–1.787 | opticalprop = Biaxial (−) | birefringence = | 2V = ~0° | pleochroism = X = blood-red; Y = pale yellow; Z = sea-green | streak = Gray to faint brown | gravity = 3.83 (meas.), 3.94 (calc.) | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = | other = | references = }} Allactite is a rare arsenate mineral of metamorphosed manganese zinc ore deposits. It is found in Sweden and New Jersey, US. Its name originated from the Greek αλλάκτειν (allaktein) meaning "to change", referring to the strong pleochroism of the mineral.
==References==