Larvikite found in Norway. Specimens are supplied in a polythene bag in lots of 1 kg with a label.
Larvikite is defined as a monzonitic plutonic rock and is almost entirely composed of feldspar.
Due to its geochemical characteristics and its chemical composition (it contains Ca,NA and K) the so-called 'ternary' feldspar it is believed to have formed at around 30km, close the the boundary between the crust and the mantle.
Commonly, used for the facing of buildings, gravestones and pub counters. Comes from Larvik . southern Norway.