Second occurrence of bonattite

Bonattite, CuSO ₄ -3H ₂ O, first described from Elba by Garavelli in 1957, is present as vermiform aggregates in a sample from the Bonaparte River area, Lillooet District, British Columbia. The extreme indices of the British Columbia mineral were determined as 1.559 and 1.615, in good agreement with the data obtained from synthetic material by Posnjak & Tunell. The X-ray powder pattern of the Lillooet mineral is compared with those obtained from synthetic CuSO ₄ 3H ₂ O and the Elba mineral. Associated with the British Columbia bonattite is a salmon-colored sulfate of composition (Cu, Fe, Zn) SO ₄ -H ₂ O with Cu:Fe:Zn = 100:94:19. The new mineral is water-soluble, and has a hardness of about 3. Partly indexed X-ray powder data are given; the strongest lines of the measured pattern are 3.46 (10), 4.72 (5), 3.08 (5), 4.85 (4), and 2.51 Aa (4). The unit cell dimensions calculated from the powder photograph are: a = 7.480, b = 7.424, c = 7.053, beta = 114 degrees 40'. Assuming Z = 4, the calculated D is 3.281. The successful synthesis is briefly described.

This record provided courtesy of AGI/GeoRef.