Bulletin of the Geological Society of Finland (Dec 1973)
Haapalaite, a new nickel-iron sulphide of the valleriite type from East Finland
Abstract
Haapalaite is a valleriite type mineral with the composition of [Fe1.26Ni.74S2]1.610[Fe.16Mg.84(OH)2]. The mineral occurs as an accessory in a serpentinite body in Finnish Northern Karelia about 33 km NNW of the Outokumpu mine. Haapalaite is hexagonal with a0 = 3.64 Å and c0 = 34.02 Å. The strongest lines of the X-ray powder pattern are 11.34 (003), 5.67 (006), 1.841 (10.15), and 1.821 (110). The mineral shows a distinct pleochroism in reflected light; light brown to greyish brown. Anisotropism is strong; brown-red, greyish white. Its microhardness ranges from 9 to 11 with a 3 g load.