False Gemstone Name Actual Gemological Name
Adelaide ruby Almandite
African emerald Green fluorite
Alaska diamond Rock crystal (quartz)
American jade Green idocrase
American ruby Pyrope or almandite (garnet) or rose quartz
Arizona ruby Pyrope (garnet)
Arizona spinel Red or Green garnet
Arkansas diamond Rock crystal (quartz)
Balas ruby Red spinel
Blue alexandrite Color-change sapphire
Blue moonstone Artificially blue-tinted chalcedony
Bohemian chrysolite Moldavite (natural glass)
Bohemian diamond Rock crystal (quartz)
Bohemian ruby Pyrope (garnet) or rose quartz
Brazilian aquamarine Bluegreen topaz
Brazilian ruby Red or Pink topaz
Brazilian sapphire Blue tourmaline
Californian ruby Hessonite (grossular garnet)
Candy spinel Almandite (garnet)
Cape-chrysolite Green prehnite
Cape-ruby Pyrope (garnet)
Ceylon diamond Colorless zircon
Ceylon opal Opal-like glimmery moonstone
Copper lapis Azurite
German diamond Rock crystal (quartz)
German lapis Artificially blue-tinted jasper (chalcedony)
Gold topaz Citrine (quartz)
Indian jade Aventurine (quartz)
King’s topaz Yellow sapphire
Korean jade Serpentine
Lithia amethyst Kunzite (spodumene)
Lithia emerald Hiddenite (spodumene)
Madeira topaz Citrine (quartz)
Marmarosch diamond Rock crystal (quartz)
Matura diamond Colorless fired zircon
Mexican diamond Rock crystal (quartz)
Mexican jade Artificially tinted green marble
Montana ruby Red garnet
Oriental amethyst Violet sapphire
Oriental hyacinth Pink sapphire
Oreintal topaz Yellow sapphire
Palmyra topaz Brown synthetic sapphire
Salmanca topaz Citrine (quartz)
Saxon chrysolite Greenish-yellow topaz
Saxon diamond Colorless topaz
Serra topaz Citrine (quartz)
Siamese aquamarine Blue zircon
Siberian chrysolite Demantoid (garnet)
Siberian ruby Red tourmaline (rubellite tourmaline)
Simili diamond Glass imitation
Slave-diamond Colorless topaz
Smoky topaz Smoky quartz
Spanish topaz Citrine (quartz)
Strass diamond Glass imitation
Transvaal jade Green hydrogrossular garnet
Ural sapphire Blue tourmaline
Viennese turquoise Artificially blue-tinted argillaceous earth

Source: Gemstones of the World, 3rd Edition, Walter Schumann.