A rarity from Mapimi, a 1.5-cm spray of koettigite/parasymplesite standing up on limonite matrix. Koettigite is zinc arsenate hydrate and parasymplesite is iron arsenate hydrate, and because they have such a similar appearance they can only be distinguished by chemical analysis in a lab. There is an interesting discussion of this series in the Min. Record, V. 7, #4, p. 186. In any case, it is probably the koettigite and its a damned good one. Old material not found in over 2 decades and there will not be more as these levels of the mine are flooded. 4.0 x 2.8 x 1.1 cm