A gemstane or gem (an aa cried a precious or semi-precious stane, a fine gem, or jewel) is a piece o mineral, which, in cut an polished form, is uised tae mak jewelry or ither adornments. However certain rocks (such as lapis lazuli), or organic materials that are nae minerals (such as amber or jet), are an aa uised for jewelry, an are tharefore eften considered tae be gemstanes as well. Maist gemstanes are haird, but some saft minerals are uised in jewelry acause o thair luster or ither pheesical properties that hae aesthetic value. Rarity is anither characteristic that lends value tae a gemstone. Apart frae jewelry, frae earliest antiquity till the 19t century engraved gems an hairdstane carvins such as cups were major luxury art forms; the carvins o Carl Fabergé wur the last significant wirks in this tradeetion.