The calcium-titanium-iron-manganese-arsenate mineral cafarsite is very rare and seldom offered for sale by mineral dealers. This piece, from the famous Binn Valley of Switzerland, displays several, lustrous, chocolate colored octahedrons of cafarsite on a matrix of metarhyolite. The largest crystal is almost 1 cm across! Such a rich specimen is uncommon - most I have had in the past were more sparsely covered. 6.1 x 5.1 x 4.1 cm