DOLOMITE FAMILY. Gcognoslic and Geographic Situations. It occurs in serpentine, in the mine Tschistagovvskoy', on the river Mjafs, in the Government of Orenburg in ltussia. Observation. It was at one time considered to he a variety of Stron- tianite; but in external characters, it is much more nearly allied to Tremolite. Fourth Subspecies. Compact Dolomite, or Magnesian Limestone. This subspecies is subdivided into two kinds, viz. Com mon Compact Dolomite, and Flexible Compact Dolo mite. First Kind. Common Compact Dolomite. Magnesian Limestone, Tennant. Tennant, Transactions of Royal Society of London for 1799-— Thomson, Annals of Philosophy for December IS 14. External Characters. * Its colours are yellowish-grey, yellowish-brown, and a colour intermediate between chesnut-brown and yellow- * ish-brown ; seldom bluish-grey. It occurs massive. Internally it is glistening or glimmering, and the lustre is between pearly and vitreous. The
