Garnet in Limestone

Although marketed commercially as "garnet in Limestone", it is more likely a calc-silicate skarn, which typically forms in the contact zone where a silica-rich intrusion undergoes contact metamorphism with limestone. Within this rock, one can often find brown to deep red garnets belonging to the grossular-andradite solid-solution series. These garnets occur as isolated crystals set against a background of white-grayish groundmass, likely composed of recrystallized calcite, wollastonite, or diopside.