Here's a nice jet-black specimen, with high luster, that shows some intricate, uneven growth habits on its faces. The biggest face showing what appears to be a spiral growth feature. Neat!
This is an example of one of three types of andradite garnet, namely the variety Melanite, named after the Greek word "melanos", meaning black, due to the presence of Titanium. These intergrown dodecahedral crystals occur in skarn zones in contact metamorphosed, impure limestones. The matrix is composed of massive albite, a plagioclase feldspar mineral. From the famous Draa-Tafilalet region of Morocco.
DDJ