gahnite
N แร่ช นิดหนึ่ง สี เขียว ดำ rae-cha-nid-nueng-si-khiao-dam
GAHNITE
n.[from Gahn, the discoverer. ] A mineral, called also automalite and octahedral corundum. It is always crystallized in regular octahedrons, or in tetrahedrons with truncated angles.
Gahn "ite, n. Etym: [Named after Gahn, a Swedish chemist. ] (Min. )