State Rocks, Minerals & Gemstones

A Collective Look at our Geosymbols

- BY STEVE VOYNICK

Galena, or lead sulfide, the primary ore of lead, is the state mineral of Kansas, Wisconsin, and Missouri. Wikimedia Commons

What do emerald, coal, marble, galena, agate and serpentinite have in common? Geologically and mineralogically speaking, not much. Yet all share membership in a rather elite club composed of “geosymbols”—mineral materials that legislators have formally designated as their states’ official rocks, minerals and gemstones.

Sapphire is one of Montana's two state gemstones. Wikimedia Commons

Every state except North Dakota has at least one geosymbol. Nineteen states have two geosymbols, while fifteen have three. Among the better-known geosymbols are California gold, Missouri galena and Arizona turquoise. Lesser-known geosymbols include Delaware sillimanite, Oregon awaruite and Rhode Island bowenite.

Considered collectively, the list of 97 state rocks, minerals and gemstones paints an interesting cultural, historical, mineralogical and economic picture of their respective states and of the nation as a whole.

New Jersey's state mineral is franklinite, a fluorescent zinc iron oxide and former source of zinc that occurs only in the Garden State. Wikimedia Commons

A GEOSYMBOL HISTORY

State symbols, beginning with flowers, first appeared in the 1890s. By the 1920s, naming state birds had become trendy. Since then, states have designated everything from reptiles, animals, insects and fish to fruit, dogs, sandwiches and even cookies as official symbols.