Kimzeyite

Kimzeyite is a rare garnet distinguished by abundant zirconium (and some titanium) in its octahedral site, with aluminum and ferric iron substituting in the tetrahedral site. This unusual chemistry ties it to alkaline, carbonate-rich magmatic environments.

It is dark brown to reddish brown, isometric, hard, and vitreous to resinous, typically occurring as small crystals or grains rather than large gem-quality material.

Kimzeyite was first described from Magnet Cove, Arkansas, and named for the Kimzey family associated with that classic mineral locality.

Kimzeyite forms in carbonatites and silica-undersaturated alkaline igneous rocks, where zirconium can be concentrated enough to enter the garnet structure. These magmas are rich in calcium, alkalis, titanium, and rare elements.

It occurs with other exotic carbonatite and alkaline-rock minerals such as perovskite, melanite-schorlomite garnet, calcite, and apatite.

Besides the type locality at Magnet Cove, Arkansas, kimzeyite has been reported from carbonatite complexes in East Africa, Italy, and elsewhere.

Look for small dark brown to reddish-brown isometric garnet crystals in carbonatite or alkaline igneous rock. Hardness is about 7-7.5, the luster vitreous to resinous, and the streak pale.

Kimzeyite closely resembles schorlomite, morimotoite, and kerimasite, all dark high-field-strength-element garnets; only chemical analysis showing dominant zirconium confirms kimzeyite. The carbonatite setting helps distinguish it from common andradite or melanite in ordinary igneous rocks.

Kimzeyite has no gem or industrial application; it is too rare and dark. Its significance is scientific and to collectors, as it records zirconium enrichment in carbonatite magmas and helps petrologists trace the behavior of high-field-strength elements.

Specimens from Magnet Cove and other carbonatite localities are valued by collectors of rare garnet-group species. It has no established metaphysical tradition.