Theo Mineralog

Staurolites

from Rear Trunk 3/99

Mineralog index

Legend has it that when Christ was crucified the angels wept and their tears turned to crosses of stone when they fell upon the earth...hence staurolites. Angel tears, fairy crosses, lagrimes de Christo, the naturally formed crosses that lie hidden in the Sangre do Christo Mountains of Southern Colorado and New Mexico have been given many names. Their technical name is staurolite and they are made of iron, aluminum and silica. Two identical crystals are usually twinned at right angles to each other to form a naturally faceted cross, brown to black in color. Sometimes the twins are locked together to form an "X" instead. You can find them embedded in shiny, striped rock formations east of the Rio Grande Gorge in the steep canyons that climb toward Picuris Peak. If you are lucky you can pick up a few in the bottom of the arroyos, pried loose from their bedrock by heat and cold, and by abrasion from debris-laden streams that follow the melting glaciers a relatively few thousand years ago. Geologists say they were formed when rock layers formed from hot, molten portions of the earth. Heat and pressure melted the ancient sediments and new minerals grew slowly as the great mass cooled. Staurolites and garnets, small reddish crystals were formed.