hedenbergite
A mineral name; a member of the pyroxene group, specifically the iron-rich endmember of the diopside-hedenbergite series. Used in geology and mineralogy.
Hedenbergite is often found in skarn deposits.
透輝石 (diopside) is the magnesium-rich endmember of the same series, while 灰鉄輝石 is the iron-rich endmember.
The Japanese name 灰鉄輝石 is a compound of 灰 (kai, 'ash' or 'gray'), 鉄 (tetsu, 'iron'), and 輝石 (kiseki, 'pyroxene'), reflecting its iron content and grayish color. The English name 'hedenbergite' honors the Swedish chemist M. A. L. Hedenberg.