Mineral description : Apophyllite

Apophyllite in prehnite from Bredsjönäs.
Apophyllite in prehnite from Bredsjönäs.
Apophyllite from Jalgaon, Maharastra, India.
Apophyllite from Aitik.

Mineral class Silicates : Phyllosilicates : Serpentinite - talc - Pyrophyllite group
Chemical formula KCa4F2(Si4O10)2*8H2O
Crystal system Tetragonal
Habitus As tetragonal crystals with cube or octaedric form. Also as foliated massive aggregates.
Cleavage Perfect basally, uneven fracture.
Hardness 4.5-5
Density 2.33-2.37
Color Colorless to white, sometimes with a red, green or yellowish hue.
Streak White
Luster Vitreous.
Notes Gives violet flame color.
Soluble in hydrocloric acid.
Apophyllite is now divided into the separate minerals fluorapophylite, hydroxylapophylite and natroapophylite.
Locations A rare mineral in Sweden.
  • Nordmarks mines, Värmland. Pyramidic or foliated crystal groups, often in cracks in the iron ore.
  • Utö iron mine, in the arkipelago of Stockholm. As clear to slightly read large crystals.
  • Bredsjönäs, Skottvång, Södermanland. As thick druses or spherical aggregates in holes in the rock.
  • Långban, Värmland. As thin pink foliated masses in andradite scarn.
  • Sörgruvan, Hällestad, Östergötland. Foliated masses together with calcite crystals.
  • Dannemora mines. In druses together with babingtonite.
  • Alnön, Sundsvall. In small amounts.

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Last changed : 2000-06-05