then, its attractive and distinctive appearance has led to increased demand from Swiss and Italian lapidaries and local jewelers. It is estimated that a few hundred pieces (mostly cabochons) have been polished from this blueschist to date. In recent years, the annual production of rough blueschist has been in the range of a few hundred kilograms. Blueschist is formed by the relatively high-pressure and low-temperature metamorphism of mafic rocks such as basalt. The overall blue color is due to

more »

... he predominance of glaucophane (a sodic amphibole) in the rock. Outcrops of blueschist in the Aosta Valley are usually accompanied by eclogite and phengite schist (figure 2 ). Although blueschist is locally abundant and may form masses up to several meters wide, lapidary-grade material is quite rare, occurring as layers and lenses up to 30 cm thick. Such blueschist has a compact texture and is glaucophane-rich and mica-poor. These outcrops are found at elevations from 300 to 2,500 m, mostly in very steep, rugged terrain. Because of this, access is possible only by foot in most cases, and mining is commonly done by local collectors using simple hand tools. COLORED STONES AND ORGANIC MATERIALS Ornamental blueschist from northern Italy. During the late 1990s, blueschist from a small number of localities in the lower Aosta Valley of the western Italian Alps was recognized as an ornamental material and polished into cabochons, beads, and other objects (see, e.g., figure 1 ). Since Editor's note: The initials at the end of each item identify the editor or contributing editor who provided it. Full names and affiliations are given for other contributors. Dr. Mary L. Johnson of the GIA Laboratory in Carlsbad is thanked for her internal review of the Gem News International section.