Gahnite, ZnAl 2 O 4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia.

May 9, 2024 · Gahnite is a mineral belonging to the spinel group, specifically a zinc aluminum oxide with the chemical formula ZnAl2O4ZnAl_2O_4ZnAl2 O4 . It is typically found in metamorphic and pegmatitic rocks and is known for its characteristic dark green, blue-green, or blue-black color, which can vary depending on its composition.

Named in 1807 by Baron Karl Marie Ehrenbert von Moll in honor of Swedish chemist and mineralogist, Johan Gottlieb Gahn [August 19, 1745 Voxna Bruk, Hälsingland, Sweden - December 8, 1818 Falun, Sweden]. The new name replaced automalite named by Anders Gustav Ekeberg. ⓘ Falun mine, Falun, Dalarna County, Sweden.

Occurrence: An accessory mineral in granites and granite pegmatites; in medium- to high-grade metamorphic rocks and metamorphosed base-metal sulfide deposits; in diasporites, formed by the low-grade metamorphism of bauxites; a detrital mineral in placers.

May 15, 2019 · The spinels from Kagoro have been identified as gahnite, the zinc end member. Gahnite is one of the rarer members of the spinel group of minerals, typically found at zinc deposits. Most crystals are very small, included, and translucent to opaque.

Gahnite is a rare zinc-bearing member of the Spinel Group that was named in 1807, but the species has been known prior to its naming. This thumbnail specimen is a rarely seen example from Broken Hill in New South Wales, Australia.

gahnite, the mineral zinc aluminum oxide, a member of the spinel (q.v.) series. This article was most recently revised and updated by Amy Tikkanen.

Gahnite. Comments: Deep blue octahedral crystals of gahnite in quartz. Location: Franklin, Sussex County, New Jersey, USA. Scale: See Photo. © Jeff Weissman / Photographic Guide to Mineral Species

Gahnite is one of the rarer members of the Spinel Group of minerals, an important group of oxides. It is named after Swedish chemist L. G. Gahn, who discovered manganese. Gahnite forms in some granitic pegmatites, zinc deposits and in skarns, a special type of contact metamorphic rock. Gahnite produces crystals showing well formed octahedrons.

Gahnite is generally identified by its octahedral crystals, luster, transparency or translucency, superior hardness, and occurrence within the orebodies. By far the most interesting and significant textural aspects of gahnite are the exsolution relations …