Emerald Emerald Emerald is a gemstone and a variety of the mineral beryl (BeAl(SiO)) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate. The word "emerald" is derived (via and ), from Vulgar Latin: "esmaralda"/"esmaraldus", a variant of Latin "smaragdus", which originated in (smaragdos; "green gem"). Emeralds, like all colored gemstones, are graded using four basic parameters–the four "C"s of connoisseurship: "color", "clarity," "cut" and "carat weight". Normally, in the
Gemstone Gemstone A gemstone (also called a gem, fine gem, jewel, precious stone, or semi-precious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli and opal) and occasionally organic materials that are not minerals (such as amber, jet, and pearl) are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another