Mineralape

Woodallite

Mg6Cr2(OH)16Cl2·4H2O
Trigonal IMA approved

Woodallite is a rare mineral with the chemical formula magnesium hexachromium didecahydroxide dichloride tetrahydrate. It belongs to the trigonal crystal system and is classified under the Strunz system as 4.FL.05. This mineral is characterized by its soft, waxy luster and typically appears in a greenish or yellowish color. With a low hardness on the Mohs scale and a relatively low density, woodallite is a hydrous chloride hydroxide mineral. It is part of the broader group of sheet silicates and is notable for its complex chemical composition and unique crystal structure.

Composition

Composizione (% in peso)
O
Mg
Cr
Cl
  • OOxygen48.1%
  • MgMagnesium21.9%
  • CrChromium15.6%
  • ClChlorine10.7%
  • HHydrogen3.6%

Overview

Woodallite is a rare mineral with the chemical formula magnesium hexachromium didecahydroxide dichloride tetrahydrate. It belongs to the trigonal crystal system and is classified under the Strunz system as 4.FL.05. This mineral is characterized by its soft, waxy luster and typically appears in a greenish or yellowish color. With a low hardness on the Mohs scale and a relatively low density, woodallite is a hydrous chloride hydroxide mineral. It is part of the broader group of sheet silicates and is notable for its complex chemical composition and unique crystal structure.

Etymology

Woodallite is named after Roy Woodall, in recognition of his contributions to mineralogy. The mineral was approved by the International Mineralogical Association (IMA) but no specific discovery year is provided in the facts.

How to recognize it

Woodallite can be identified by its soft, waxy luster and low hardness, though the exact Mohs hardness is not specified in the facts. It typically exhibits a greenish or yellowish color and may be distinguished by its unique chemical composition and crystal system. Due to its rarity and specific properties, it is less commonly confused with other minerals, though detailed identification methods are not provided in the facts.

Trivia

Woodallite is notable for its complex chemical formula, which includes multiple hydroxide and chloride ions. It belongs to the rare trigonal crystal system and is part of a unique classification within the Strunz system. The mineral is named after Roy Woodall, highlighting its significance in honoring contributions to mineralogy.

Frequently asked questions

Yes, woodallite is considered a rare mineral, with limited known occurrences worldwide.