Gahnite, ZnAl₂O₄, is a rare mineral belonging to the spinel

Spinel

Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...

 group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It occurs in Falun

Falun

Falun is a city and the seat of Falun Municipality in Dalarna County, Sweden, with 36,447 inhabitants in 2005. It is also the capital of Dalarna County...

, Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 where it is found in pegmatites and skarn

Skarn

Skarn is an old Swedish mining term originally used to describe a type of silicate gangue, or waste rock, associated with iron-ore bearing sulfide deposits apparently replacing Archean age limestones in Sweden's Persberg mining district. In modern usage the term "skarn" has been expanded to refer...

s, contact metamorphic rocks. Other occurrences include Charlemont, Massachusetts

Charlemont, Massachusetts

Charlemont is a town in Franklin County, Massachusetts, United States. The population was 1,358 at the 2000 census. It is part of the Springfield, Massachusetts Metropolitan Statistical Area.- History :...

; Spruce Pine, North Carolina

Spruce Pine, North Carolina

Spruce Pine is a town in Mitchell County, North Carolina, United States. The population was 2,175 at the 2010 census.-History:Spruce Pine was founded in 1907 when the Clinchfield Railroad made its way up the North Toe River from Erwin, Tennessee...

; White Picacho district, Arizona; Topsham, Maine; and Franklin, New Jersey

Franklin, New Jersey

Franklin is a Borough in Sussex County, New Jersey, United States. As of the 2010 United States Census, the borough population was 5,045.Franklin, known as the "Fluorescent Mineral Capital of the World," is located over a rich ore body containing more than 150 minerals, many of them fluorescent and...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

.

It was first described in 1807 for an occurrence in the Falu mine, Falun, Dalarna, Sweden, and named after the Swedish chemist, Johan Gottlieb Gahn

Johan Gottlieb Gahn

Johan Gottlieb Gahn was a Swedish chemist and metallurgist who discovered manganese in 1774.Gahn studied in Uppsala 1762-1770 and became acquainted with chemists Torbern Bergman och Carl Wilhelm Scheele...

 (1745-1818), the discoverer of the element manganese

Manganese

Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

. It is sometimes called zinc spinel.