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 (Fe<sup>2+</sup>,Mg)(OH)<sub>2</sub>. 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:
Amakinite is slightly magnetic and was named for the Amakin Expedition, which prospected the diamond deposits of Yakutia in the Russian Far East.