GROSSULAR

HISTORY, NAME, LOCALITIES:  Grossular, pronounced GRAHS-yuh-lar, has been known since antiquity.  Its name was assigned in 1819 and stems from Ribas grossularium, the botanical name for gooseberry, alluding to the similarity of color between gooseberries and the green variety of grossular.  Notable collecting localities are found in Canada, Brazil, Czech Republic, Mexico, Sri Lanka, Russia, Kenya, and the United States (California, Colorado, Arizona).

MINERALOGY, PROPERTIES, OCCURRENCE: Grossular [calcium aluminum silicate, Ca₃Al₂(SiO₄)₃], one of 15 members of the garnet group, crystallizes in the isomeric system as dodecahedrons and trapezohedrons.  It has a Mohs hardness of 7.0-7.3, a vitreous luster, no cleavage, and a specific gravity of 3.6-4.3.  It is colorless or white when pure, but usually exhibits colors ranging from red and orange-brown to yellow, yellow-green, green, and brown.  Grossular forms mainly through metamorphic processes and occurs in schist, gneiss, and altered limestone.

METAPHYSICAL PROPERTIES, LORE, USES:  Metaphysical practitioners believe that grossular controls the flow of psychic energies, enhances creativity, supports altruistic pursuits, and provides one with strength when facing challenges.  The

brilliant-green variety of grossular is the valuable gemstone tsavorite; hessonite is the orange gem variety.  Grossular is among the garnet-group minerals that are mined for use as industrial abrasives and filtration mediums.

COLLECTORS’ INFORMATION: Grossular is collected for its wide range of colors, excellent dodecahedral and trapezohedral crystal development, and association in composite specimens with other metamorphic minerals.