Superb Terminated Crystal Of Hellandite-(Y)
Lindvikskollen Pegmatite, Kragero, Telemark, Norway
Small Cabinet, 6.0 x 3.0 x 3.0 cm
Ex. Rock Currier
Spectacular, 5cm long, terminated, off-white, monoclinic crystal of the rare earth-bearing silicoborate hellandite-(Y) that has been tectonically fractured and re-healed to form an undulating prism. The top termination is well defined and exhibits incipient alteration to an unidentified light olive green mineral. The bottom termination is incomplete, probably due to juxtaposed growth against another mineral such as quartz or orthoclase that are both in association along with minute, vitreous, black-brown spots of a metamict species. This is a huge crystal with a fascinating growth history as well as an interesting pedigree. It has an experienced 1903, Natural History Museum, Oslo, handwritten label along with a Burminco label.