JOHANNSENITE with SPHALERITE (miniature)

Johannsenite, CaMn²⁺Si₂O₆ is a rare silicate mineral belonging to the pyroxene family, formed either in limestone or through metamorphic processes. It is often linked with lead-zinc mineralization and is considered relatively rare, although it is reported to be plentiful in Arizona's Aravaipa region. Typically, it appears as spherulite-like aggregates. Johannsenite is susceptible to oxidation, hydration, and carbonation, and it frequently undergoes alteration to rhodonite. The mineral was named in 1932 in honor of Albert Johannsen.

Former John Betts Collection, New York # 12027