WHAT MAKES THE BEAUTY (AND THE VALUE) OF A GEM?
Color is the main criterion. The color must be deep, pleasing, well saturated. Grading criteria include the hue, and the tone. The later must not be too light, or too dark. Clarity is the second main criterion. Gemstones that will be cut into facetted shapes must be as clear as water. Inclusions and cracks are tolerated, but the top grades have neither. Translucent or opaque gems that still display a pleasant color are fashioned into cabochons or beads. Size plays an important role in gemstone pricing. Large stones are much more rare than small stones, and accordingly are priced at a much higher level. EAST AFRICA GEMSTONES Away from major traditional gemstone producing countries such as Sri Lanka, Burma or Thailand, the East African region has long been virtually unknown as a source of gemstones. In the mid 1960s, striking discoveries were made in Tanzania: sapphire, ruby, emerald, aquamarine… But the most important of these discoveries were two new gemstones: tanzanite, a vivid blue
