Each month this section will feature either a topic of interest to gem lovers or one special gemstone with background on the material and its value.

Apatite, a stone seldom found in jewelry stores and only recently known to the general public, is beloved by collectors for its many different colors and forms. Only with the recent availability of the neon blue-green variety from Madagascar has its jewelry use increased. The color of the best specimens of this type rivals the famed Paraiba tourmalines, but alas, this gem lacks their toughness and hardness. At 5 on the Mohs scale, and a tendency to cleave, apatite must be cut, set, and worn gently. Earrings, pendants, pins and tie tacks are probably safe, but ring and bracelet use should be limited to occasional wear pieces with protective settings.

Care for this stone is similar to that given opals, it is heat and shock sensitive, so steamers and ultrasonics must be avoided. Only occasionally cut as cabochons and beads, the greatest use is in faceted stones.

Gems are available in yellows and various shades of blues and greens, some of the blues and yellows show chatoyancy and can be cut as cat's eyes. Main sources are Brazil, Canada, India, Mozambique and Madagascar.

In today's market, the neon blue green stones are valued much more highly than green or yellow stones. The rarest of all varieties, a rich purple from Maine, tops the list. Degree of polish can vary on this soft stone due to skill levels of individual cutters, giving well polished stones premium value. As with most gems, saturation of color, size and clarity are the major determiners of value. Cat'seyes also fetch good prices.