Halotrichite

Halotrichite, also known as feather alum, is a highly <a href="/facts/Hydrate/dev82l69">hydrated</a> sulfate of <a href="/facts/Aluminium/7wmR8jYE">aluminium</a> and <a href="/facts/Iron/QK1JYy8E">iron</a>. Its chemical formula is FeAl2(SO4)4·22H2O. It forms fibrous monoclinic crystals. The crystals are water-soluble.
It is formed by the weathering and decomposition of <a href="/facts/Pyrite/41CYREyr">pyrite</a> commonly near or in <a href="/facts/Volcanic/c2M5upml">volcanic</a> vents. The locations of natural occurrences include: the <a href="/facts/Atacama_Desert/RmLNNvvg">Atacama Desert</a>, <a href="/facts/Chile/uEyTfEcx">Chile</a>; <a href="/facts/Dresden/nKVXxIgq">Dresden</a> in <a href="/facts/Saxony/PrKscwCP">Saxony</a>, <a href="/facts/Germany/paluuWBX">Germany</a>; <a href="/facts/San_Juan_County,_Utah/RU01pAcC">San Juan County, Utah</a>; <a href="/facts/Iceland/E4KGYs2j">Iceland</a>; <a href="/facts/Idrija/Ml2xt91M">Idrija</a>, <a href="/facts/Slovenia/EcYU22W4">Slovenia</a>; and <a href="/facts/Mont_Saint-Hilaire/ufjxSdlG">Mont Saint-Hilaire</a>, <a href="/facts/Canada/cWWFM8oc">Canada</a>.
The name is from <a href="/facts/Latin/pM3Kge85">Latin</a>: halotrichum for salt hair which accurately describes the <a href="/facts/Precipitate/s3BgsLLY">precipitate</a>/<a href="/facts/Evaporite/vNW8fcEy">evaporite</a> mineral.

Gallery

<ul><li><a href="http://www.saint-hilaire.ca/en/halotri.htm">Saint-Hilaire</a></li>
<li><a href="https://web.archive.org/web/20061124193345/http://www.mineralatlas.com/mineral%20general%20descriptions/H/halotrichitepcd.htm">Mineral Atlas</a>[usurped]</li></ul>

Halotrichite open-in-new

Halotrichite