Another traditional term for semi-precious gemstones used in art history and archaeology is hardstone.

The traditional distinction does not necessarily reflect modern values for example, while garnets are relatively inexpensive, a green garnet called tsavorite can be far more valuable than a mid-quality emerald. Other stones are classified by their color, translucency, and hardness. This distinction reflects the rarity of the respective stones in ancient times, as well as their quality: all are translucent with fine color in their purest forms, except for the colorless diamond, and very hard, with hardnesses of 8 to 10 on the Mohs scale. In modern use, the precious stones are emerald, ruby, sapphire and diamond, with all other gemstones being semi-precious. The traditional classification in the West, which goes back to the ancient Greeks, begins with a distinction between precious and semi-precious similar distinctions are made in other cultures. The largest pebble here is 40 mm (1.6 in) long. A gem expert is a gemologist, a gem maker is called a lapidarist or gemcutter a diamond cutter is called a diamantaire.Ĭharacteristics and classification Ī collection of gemstone pebbles made by tumbling the rough stones, except the ruby and tourmaline, with abrasive grit inside a rotating barrel.

Īpart from jewelry, from earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms. Rarity and notoriety are other characteristics that lend value to gemstones.įound all over the world, the industry of coloured gemstones (this meaning anything other than diamonds) is currently estimated to be around 10-12 million US dollars. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. However, certain rocks (such as lapis lazuli, opal, and obsidian) 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. Group of precious and semiprecious stones-both uncut and faceted-including ( clockwise from top left) diamond, uncut synthetic sapphire, ruby, uncut emerald, and amethyst crystal cluster.Ī gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments.

Amethyst gemstone worth