DIRK WIERSMA / SCIENCE PHOTO LIBRARY DIRK WIERSMA / SCIENCE PHOTO LIBRARY
Garnets are a group of silicate minerals that comprise different species among which the most common are pyrope, almandine, spessartine and grossular. All possess similar physical properties and crystal forms, but differ in chemical composition. The species in this sample is, on a schistose substrate, is almandine, the iron-alumina variety with chemical formula Fe3Al2(SiO4)3. It has a characteristic brownish red colour, more rarely tending towards purple or violet. It occurs in schist and other metamorphic rocks, often in well-developed rhombic dodecahedra as seen in this sample. From the Otztal, Tirol, Austria. Actual width of sample is 40 cm. Same sample as 214030050.
Model release not required. Property release not required.