Minehillite is a relatively rare mineral typically occurring as a secondary mineral in zinc- and manganese-rich hydrothermal veins. It belongs to the carbonate mineral group and specifically to the dolomite series. The mineral derives its name from the type locality, Mine Hill, Franklin, New Jersey, where it was first discovered.
Minehillite possesses a unique crystal structure characterized by the alternation of calcium and manganese layers. It crystallizes in the trigonal system and is often found in the form of small, prismatic crystals or grainy aggregates. The color of minehillite can vary, but it is commonly found in pale yellow, brownish-yellow, or light pink hues. It exhibits a vitreous to dull luster, and its transparent to translucent nature allows light to pass through the mineral.
In terms of physical properties, minehillite has a relatively low Mohs hardness, typically ranging from 3 to 4. It has a brittle tenacity and a perfect cleavage in three directions. When subjected to hydrochloric acid, minehillite effervesces and produces an observable reaction.
While minehillite is not widely used for commercial purposes due to its scarcity, its unique properties and aesthetic appeal make it popular among mineral collectors. Its occurrence in various locations worldwide, including the United States, Kazakhstan, and Germany, adds to its allure. Nonetheless, its limited occurrence and lack of widespread use restrict the detailed knowledge and applications of minehillite in various fields.
