GEM n.
A precious stone of any kind, as the ruby, emerald, topaz, sapphire, beryl, spinel, etc., especially when cut and polished for ornament; a jewel. Milton.
GNEISS n.
ock, consisting, like granite, of quartz, feldspar, and mica, but having these materials, especially the mica, arranged in planes, so that it breaks rather easily into coarse slabs or flags. Hornblende sometimes takes the place of the mica, and it is then called hornblendic or syenitic gneiss. Similar varieties of rela…