Precious gemstones – Diamond, Ruby, Sapphire, Emerald Semi-precious gemstones – Agate, Alexandrite, Amethyst, Aquamarine, Beryl, Citrine, Garnet, Opal, Spinel, Tanzanite, Topaz, Turquoise, Tourmaline, Zircon, Peridot When purchasing a gemstone there are the five characteristics to consider: COLOR – The color of a gemstone it its most defining feature. When deciding upon a gemstone color it is important to look at …