First Report of Domeykite and Koutekite (Copper Arsenides) in Siwalik Sandstones of Romehra, Hamirpur District, Himachal Pradesh

Abstract

Koutekite and two polymorphs (i.e., alpha and beta) of domeykite (rare copper arsenide minerals) are reported for the first time from the uraniferous Lower Siwalik sandstones of the Romehra area, Hamirpur district, Himachal Pradesh. The calculated cell size of . alpha-domeykite (Cubic) is a₀ = 9.646 í… and that of betadomeykite (Hexagonal) is a₀ = 7.151 í… and c₀ = 7.304 í…. Koutekite (Hexagonal) has measured cell parameters of a₀ = 11.58 í… and c₀ = 14.55 í…. However, in koutekite of Romehra area an important interplanar spacing (d) at 2.081í… is merging with 'd' of beta dorneykite at 2.061í… and another interplanar spacing at 2.47í… exhibits comparatively higher intensity than the one published in JCPDS Data Card No.13-581. Association of domeykite with uraniferous sandstones points out that uranium mineralisation in Lower Siwaliks of the Romehra took place possibly below 90°C temperature.