Amakinite

Amakinite (IMA symbol: Amk) is a semi transparent yellow-green hydroxide mineral belonging to the brucite group that was discovered in 1962. Its chemical formula is written as (Fe2+,Mg)(OH)2. It usually occurs in the form of splotchy, anhedral crystals forming within a group or structure in other minerals or rocks, such as kimberlite (occurring in diamond-rich eruptive pipe). Its composition is as follows:

Magnesium 5.82% Mg 9.66% MgO Manganese 6.58% Mn 8.50% MnO Iron 46.84% Fe 60.26% FeO Hydrogen 2.42% H 21.58% H2O Oxygen 38.34% O Amakinite is slightly magnetic and was named for the Amakin Expedition, which prospected the diamond deposits of Yakutia in the Russian Far East.