In some minerals color is directly related to a metallic element, is characteristic, and can be useful in identification. As examples, azurite as shown in Figure 1A, is always blue due to the presence of copper, and rhodochrosite, shown in Figure 1B, is always pink to red due to the presence of manganese,. However minerals. . . Read More
CLEAVAGE IN A MINERAL CRYSTAL[Ref1] Cleavage in a mineral is the tendency for the crystal to split along definite crystallographic planes as exemplified by the rhombohedron cleaved from a calcite crystal shown in Figure 1[Ref1]. These planes of weakness are present within a regular repeating array of atoms and ions within the crystal and are. . . Read More
Meteorites are stuff from outer space; each is a solid piece of debris which formed from dust within the protoplanetary disc or from object such as an asteroid, planetesimal, or planet, and which travels through space and falls through the atmosphere to the surface of earth. As alien objects which fall dramatically they have evoked. . . Read More
Art Deco is my favorite style of jewelry, with its flair of design and the use of unusual combinations of gemstones. Art Deco is a style of architecture and design which first appeared in France just before World War I, reached its high point during the 1925 Paris Exposition of Decorative Arts, and extended into. . . Read More
We usually think of star sapphires and rubies as stones in the few carat range, not in hundreds and thousands of carats. But some are an amazing size. At the top, are the World’s Largest which are truly awesome. In this blog I’ll describe the worlds largest blue star sapphire, star ruby, and black star. . . Read More
Gemstones of the mineral corundum [Ref 1] offer a rainbow of colors for the lapidarist and jewelry maker as displayed in Figure 1. Traditionally, of these, the ruby and blue sapphire, along with diamond and emerald, are considered to be the four-membered family of precious gems. Corundum gemstones, other than the ruby and blue sapphire,. . . Read More
I’ve assembled a gallery of 15 fluorite specimens from some of the locations around the world which are favored by collectors.