This Specimen has been sold.
6.3" Polished Tinguaite Slab - Khibiny Massif, Russia
This is a 6.3" wide slab of tinguaite that was collected from the Khibiny Mountains of Murmansk Oblast, Russia. It has been polished to a glossy finish on one side and is accompanied by an acrylic display stand.
Tinguaite is a fine grained igneous rock, and is a variety of phonolite. It is comprised of a variety of minerals including nepheline, alkali feldspar, aegirine, and in some cases biotite. These mineral aggregations can often give it a felt-like appearance and a brown, black, and green coloration. Some notable sites where tinguaite occurs are the United States (Montana), Brazil (Rio De Janeiro), Russia (Murmansk Oblast), and Norway (Hedrum).