IMCN15 Magnetite (Dodecahedral!)
Neimeng, Chifeng, Inner Mongolia, China
20.8x 13.7x 5.2 cm
A large cabinet cluster of DODECAHEDRAL magentite crystals.
This form is highly unusual in magnetite, except (I am told) in skarn deposits. Everywhere else, they are usually octahedral—think back to the Bolivian pieces, or the loose brazilian octahedrons.
I have seen a few of these now, but none of the crystals have been nearly as large, and they have always been tightly clustered masses closely resembling the andradites from the same locality, except with a more metallic appearance and (usually) striated faces. The two minerals have tended to look so similar in fact, that I saw a couple magnetites being offered as garnets.