thaumasite

[Greek thaumazō to be surprised; suff. -ite ( Min.).] Min .: An amorphous mineral occurring in crevices in the Bjelke mine, Jemtland, Sweden. When first found it is stated to be soft, hardening on exposure. Hardne , 3.5; specific gravity, 1877; luster, greasy to dull; color, white. Composition: A mean of three very concordant analyses appears to justify the formula suggested by Lindström, CaSiO3+CaCO3+CaSO4+14 aq., which needs silica, 9.93; carbonic acid, 7.28; sulphuric acid, 13-25; lime, 27.82; water, 41.72=100. In view of the im probable composition, it has been attempted to show that the substance is a mixture; but by independent microscopic investigation its practically homogeneous structure has been confirmed. Still further examination is e ential.