A ball of dark bluish-green crystals of köttigite, centred on matrix. Köttigite is the Zn-bearing end-member of the köttigite-parasymplesite series (parasymplesite is the Fe-bearing end-member) – analysis provided by Jordi Fabre has confirmed that this particular specimen is an iron-bearing köttigite. Upon inspection with magnification, one can see tiny coatings of yellow pharmacosiderite. This specimen is from the Tracy Kimmel collection – it was in the David Stoudt collection and then Tracy acquired it from Jordi (their labels are included – unfortunately, Tracy didn’t have labels of her own). It is mounted on an acrylic base – I can certainly remove it if you’d prefer – just let me know. This is a beautifully-proportioned specimen of this uncommon mineral – the specimen is photographed on mindat and also included in Jordi’s new online mineral museum.

About Tracy Kimmel (click here)