Mineral Species: Garnet var. Almandine

Chemical Formula: Fe3Al2(SiO4)3

Chemical Name: Iron Aluminum Silicate

Mineral Class: Nesosilicate

Mineral Notes: Almandine is the most common type of Garnet and is usually the variety found in Garnet Schists. Gemmy transparent crystals are frequently used in jewellery along with Pyrope. Almandine, like other garnets, forms rounded crystals with 12 rhombic or 24 trapezoidal faces or combinations of these. This crystal habit is classic for the group. Almandine is the iron aluminum garnet end member of the group. Magnesium can substitute for the iron to become Pyrope, the magnesium aluminum garnet. Pure Almandine and pure Pyrope are rare in nature and most specimens are a series between the two. The change in density from Almandine (4.3) to Pyrope (3.6) is the only certain way to distinguish the minerals apart.

Description: A matrix of mica Schist studded by well-formed crystals of Almandine. These show the classic garnet habit. On the surface of the Schist are several indentations showing the former positions of Garnet crystals which have been eroded out of the matrix. However the remaining crystals are firmly attached and have a strong red-brown colour. A very unusual and aesthetic specimen.

Location: Salten, Nordland, Norway.