Outstanding brown yeatmanite crystals associated to zincite and franklinite from the famous Sterling mine,Sterling hill (Sterling Mine, Ogdensburg, Sussex County, New Jersey, United States of America). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Yeatmanite
Yeatmanite is an IMA-recognized mineral species in the silicate class, with the chemical formula Zn₆Mn²⁺₉Sb⁵⁺₂O₁₂(SiO₄)₄.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Katoptrite structural group.
Key properties: Mohs hardness 4; specific gravity 5.02; Very light brown streak; optically biaxial.
IMA symbol Ytm, grandfathered status — known before the IMA’s founding, named in 1938.
Found in veins in massive granular ore in a metamorphosed stratiform zinc deposit.
It is found associated with Sarkinite, willemite, calcite, diopside, andradite, rom¶eite.
The name refers to Pope Yeatman (1861–1953), mining engineer at Franklin, New Jersey, USA.