Diopside

A calcium-magnesium silicate (CaMgSi₂O₆) common in skarn formed when hot, silica-rich hydrothermal fluids from a magma intrusion react with carbonate rocks like limestone and dolostone.  Near Kimmirut, diopside (H=5.5-6.5) occurs as euhedral, dark brownish-purple to pale brown crystals, often 1 to 3 cm embedded in coarse pale-orange calcite.

Main Photo Credit: "Diopside" by NRCan, 2026. Used with permission.