In general, the edges of glass break easily, so glass "crystals" will show wear along the edges of facets, more than would be expected in gemstones. If you have a piece of real jade, clink it against the stone in question. If you see tiny flaws or irregular patterns within the stone, it is likely a real gem — although not necessarily an emerald. Gemstone will be cooler to the touch when you pick it up. There are 22 references cited in this article, which can be found at the bottom of the page. These illustrate how the density of gemstones exceeds the density of glass. I've recently been conned and should have known better! Beads that sound different from the glass beads may be … It can be difficult to tell the difference between semi-precious stones (any gemstone that isn’t a diamond, sapphire, ruby, or emerald) and imitations made from glass. Most real stones have flaws (called inclusions) of some kind. All these gemstones scratch glass, if one cares to perform a hardness test, because the hardness of glass lies between 5 and 5.5. We use cookies to make wikiHow great. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/d\/dd\/Tell-Glass-from-Semi-Precious-Stone-Beads-Step-1.jpg\/v4-460px-Tell-Glass-from-Semi-Precious-Stone-Beads-Step-1.jpg","bigUrl":"\/images\/thumb\/d\/dd\/Tell-Glass-from-Semi-Precious-Stone-Beads-Step-1.jpg\/aid10174370-v4-728px-Tell-Glass-from-Semi-Precious-Stone-Beads-Step-1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":"728","bigHeight":"546","licensing":"