Andradite rainbow garnet

10 x 9 x 7 mm overall
1.1 grams (5.5 carat)

An iridescent Japanese rainbow garnet, which is near end-member Andradite, to 10 mm. Like most, this is a partial crystal with sharp faces, and a mix of pink, yellow, orange, blue and green metallic flashes on the surface of the faces. The play of colors is from diffraction of light through a rather complex lamellar, or thin-layered, structure. These garnets first came on the market in 2002. In August 2005 collecting was strictly prohibited, with field collectors subsequently arrested. Rainbow garnets are found in only a few places in the world, and these Japanese specimens are most desirable and sought after.