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%
 * 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.