Amethyst Galleries'Mineral Gallery MINERALS Groupings Birthstones All Minerals Gemstones By Class ROCKS IGNEOUS ANDESITE ANORTHOSITE BASALT CARBONATITE DACITE DIORITE DUNITE GABBRO GRANITE KIMBERLITE KOMATIITE LAMPROPHYRES MONZONITE OBSIDIAN PEGMATITE PERIDOTITE PUMICE PYROXENITE RHYOLITE SCORIA SYENITE METAMORPHIC ...
Gemstones have attracted humankind since ancient times, and have long been used forjewelry. The primerequisitefor a gem is that it must be beautiful. The beauty may lie in colour or lack of colour; in the latter case, extreme limpidity and “fire” may provide the attraction. Iridescence, ...