Crystals of precious beads dolomite from the Midwest USA are well known for their beautiful pink color, pearly luster, and unusual crystal habit. It comes from the carbonates class and trigonal crystal system. Colorless precious beads dolomite is rarely faceted because of its softness and perfect cleavage, although some crystals are cut for collectors-usually in a step cut. Precious beads dolomite is composed by calcium magnesium carbonate. The luster is vitreous to pearly and the fracture is subconchoidal.
With refractive index range between 1.502-1.681 and specific gravity between 2.8-2.9, precious beads dolomite comprises the chief source of magnesium acquired from the crust of the earth. The hardness is stopped at 3.5-4 and the dispersion is 0.027. It is a sedimentary rock-forming mineral, and is usually mined from massive beds that can reach several hundred feet in depth. This brittle stone consists of calcium magnesium carbonate. Precious beads dolomite has a 0.179 birefringence and a perfect-in-three-directions cleavage.
Precious beads dolomite was first described in 1797 by French naturalist and geologist Deodat de Gratet de Dolomieu (1750-1801), from its occurrence in a region of the Italian Alps (now called the dolomites in his honor). Precious beads dolomite can be several different colors, but colorless and white are most common. In less number, there is also gray to pink too. The luster of precious beads dolomite is probably one of the best examples of a pearly luster. The sources of precious beads dolomite are in Mexico, Midwest USA, Spain, Switzerland, and Canada (Ontario).
Pure precious beads dolomite may appear either white or yellow natural gemstones. The habit is rhombohedra and saddle-shaped intergrowths. Small amounts of iron in the composition give the crystals a yellow to brown tint, a high manganese content can make the crystals a pale rose-pink, and cobalts turns it a more purplish pink. Precious beads dolomite looks very much like calchite, which consists only of calcium carbonate. It forms white, gray to pink, and mainly curved crystals, although the habit is normally massive. Its physical properties are similar to those of calcite.
