آلوفان
Sign in to saveAllophane is an amorphous to poorly crystalline hydrous aluminium silicate clay mineraloid. Its chemical formula is Al2O3·(SiO2)1.3-2·(2.5-3)H2O. Since it has short-range atomic order, it is a mineraloid, rather than a mineral, and can be identified by its distinctive infrared spectrum and its X-ray diffraction pattern. It was first described in 1816 in Gräfenthal, Thuringia, Germany. Allophane is a weathering or hydrothermal alteration product of volcanic glass and feldspars and sometimes has a composition similar to kaolinite but generally has a molar ratio of Al:Si = 2. It typically forms u
Key facts
- Mineral.name
- Allophane
- Mineral.image
- Allophane-352375.jpg
- Mineral.category
- Phyllosilicate minerals
- Mineral.formula
- Al2O3·(SiO2)1.3-2·(2.5-3)H2O
- Mineral.IMAsymbol
- Alp
- Mineral.strunz
- 9.ED.20
- Mineral.color
- White, pale blue to sky-blue, green, brown, yellow
- Mineral.habit
- Crusts and masses
- Mineral.system
- Amorphous
- Mineral.cleavage
- None
- Mineral.fracture
- Conchoidal
- Mineral.tenacity
- Brittle
- Mineral.mohs
- 3
- Mineral.luster
- Waxy to earthy
- Mineral.streak
- White
- Mineral.diaphaneity
- Transparent, translucent
- Mineral.gravity
- 2.8
via Wikipedia infobox
Wikidata facts
- Image
- Allophane-277529.jpg
Show 9 more facts
- Nickel-Strunz 9th edition (updated 2009)
- 9.ED.20
- Commons category
- Allophane
- Nickel-Strunz '10th ed', review of (9th ed/ 2009 update)
- 9.ED.20
- crystal system
- amorphous solid
- streak color
- white
- described by source
- Encyclopædia Britannica 11th edition
- IMA Mineral Symbol
- Alp
- chemical formula
- Al₂O₃(SiO₂)₁.₃-₂.₀·2.5-3.0H₂O
- Strunz 8th edition (series ID, updated)
- VIII/E.11 – Anhang
Sources (2)
via Wikidata · CC0