Lost Limbs Foundation

Wednesday, February 5, 2014

Twinned Galena

While we have dealt with this lead sulphide ore mineral before (seehttp://tinyurl.com/ms4vd46) , this specimen exhibits a form of contact twinning (as opposed to the interpenetrant twinned pyrite we shared recently at http://tinyurl.com/kp6nluf) that follows what mineralogists call the spinel law. Two octahedral crystals have grown together at the base, sharing some of their crystal lattice points, often in bilateral symmetry, and are separated by a twin pla...See More