gneiss — a common and widely distributed type of rock formed by regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks …
goethite — species of mineral; data; constituent of binghamite …
goshenite — variety of beryl; see goshenite in ‘Classification’ …
grandidierite — species of mineral; see grandidierite in ‘Classification’ …
grandite — synonym of grossular-andradite series …
granite — a common type of intrusive, felsic, igneous rock which is granular in texture …
green beryl — variety of beryl; see green beryl in ‘Classification’ …
greisen — a highly altered granitic rock or pegmatite …
grossular — species of mineral; see grossular in ‘Classification’ …
grossular-andradite series — a series between grossular and andradite; see grossular-andradite series in ‘Classification’ …
grossular-hibschite series — a series between grossular and hibschite; see grossular-hibschite series in ‘Classification’ …
hackmanite — variety of sodalite; see hackmanite in ‘Classification’ …
hambergite — species of mineral; see hambergite in ‘Classification’ …
haüyne — species of mineral; see haüyne in ‘Classification’ …
heart — rare shape in faceting a gemstone …
heliodor — variety of beryl; see heliodor in ‘Classification’ …
heliotrope — synonym of bloodstone …
hematite — species of mineral; see hematite in ‘Classification’ …
hemimorphite — species of mineral; see hemimorphite in ‘Classification’ …
