1.6" Hemimorphite and Rosasite Association - Utah

Rosasite is a secondary mineral that forms in oxidation zones of copper-zinc deposits, generally forming a fibrous botryoidal sphere that can appear vitreous and silky. While typically featuring a blue-green color, colorless specimens are not unheard of. The chemical formula of rosasite is CuZnCO3(OH)2.

Hemimorphite is a basic hydrous zinc silicate with the chemical composition Zn4Si2O7(OH)2 · H2O. It earned its name from the structure of which the crystals form, through greek terminology. It has two different terminations on each side of the crystal, hence the inclusion of the greek terms "hemi", meaning half and "morph", meaning shape. The crystal formations can range anywhere between a crystal druze or botryoidal formation, to radiating acicular crystals, and more. The color of these crystals have been found to be white, beige, light brown and blue. On rare occasions, yellow and green crystals have been found.

Prior to 1803, hemimorphite and smithsonite were thought to be the same mineral called "calamine". However, following further scientific research, it was concluded that these were two distinct minerals.