Recognising real stones
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How to tell a natural stone from a treated, reconstituted or synthetic one, or from an imitation: simple markers, safe tests and the limits of what you can check at home.
AuthenticityRecognising Real TurquoiseNatural, stabilised, reconstituted, dyed howlite or glass: what is on the market on the market, the signs that should raise doubts, and tests that are safe to carry out.AuthenticityRecognising Real Lapis LazuliNatural lapis lazuli, wax-treated, dyed jasper, synthetic glass or reconstituted powder: pointers and safe tests for recognising this blue rock.AuthenticityRecognising Real AmberBaltic or Burmese amber, copal, reconstituted amber, plastic and glass: pointers, the salt water test and the limits of each test, so you are not misled.AuthenticityRecognising Real CitrineMost citrine on the market is heated amethyst. Colour signs, clues in clusters, misleading names and simple, safe tests.AuthenticityRecognising Real Jade"Jade" is the name of two stones, nephrite and jadeite. Types A, B and C, imitations (serpentine, dyed quartz, glass) and simple, safe tests.AuthenticityRecognising Real OpalPrecious opal, common opal, doublet, triplet, laboratory opal or "opalite" glass: the pointers that tell you what you are buying, without risky tests.AuthenticityRecognising Real CoralPrecious coral is the skeleton of a marine animal. Red coral, dyed bamboo coral, resin and glass: pointers, safe tests and questions of protection.AuthenticityRecognising a real pearlNatural pearl, cultured pearl, freshwater pearl, pearlescent glass bead: how to tell them apart, the tooth test, and what only a laboratory can tell you.AuthenticityRecognising a real amethystNatural amethyst, lab-grown, dyed quartz or violet glass: colour clues, the trap of geodes, misleading names and simple, safe tests.AuthenticityRecognising a dyed agateBlue, pink, green, violet or uniform black: most highly coloured agates are dyed. How to spot it, what it changes, and how to care for them.AuthenticityRecognising real rose quartzNatural rose quartz, dyed quartz, pink glass or resin: colour clues, warning signs, pink stones often confused with it and simple, safe tests.AuthenticityRecognising real rock crystalRock crystal, glass, lead crystal from glassware, synthetic quartz or plastic: the differences and simple tests, including the double-line test.AuthenticityRecognising real obsidianObsidian is natural volcanic glass. How to tell it apart from manufactured black glass and false blue obsidian, its varieties, and safe tests.AuthenticityRecognising real malachiteNatural, stabilised, reconstituted or imitation malachite (glass, plastic or dyed stone): the markers that help you find your way, without any dangerous tests.AuthenticityTurquoise or dyed howliteWhite howlite, which is very porous, is dyed blue to imitate turquoise. Here are the signs, the safe tests and the label terms so you do not get it wrong.AuthenticityRock crystal or glassRock crystal (quartz), glass, lead crystal or synthetic quartz: what each material is, the useful clues, and the limits of tests done at home.AuthenticityTiger's eye, hawk's eye and bull's eyeThree names for one family of fibrous quartz: what sets them apart, the role of heating, and how to avoid “cat's eye” glass and dyed pieces.AuthenticityMoonstone, labradorite or adulariaThree names for feldspars with shifting reflections, often mixed up: adularia, rainbow moonstone and labradorite, along with their glass imitations.AuthenticityJade: nephrite, jadeite or serpentineThe word “jade” covers two minerals, nephrite and jadeite, and is also used to sell serpentine or other stones. Markers, treatments and safe tests.AuthenticityAmber, copal or plasticAmber is fossil resin; copal is a younger form of it; plastic and glass imitate it. Markers, safe tests and the limits of those tests.AuthenticityNatural, doublet or synthetic opalSolid opal, doublet, triplet, lab-grown opal or glass: what each one is, the signs to look for under a loupe, common treatments and care precautions.AuthenticityCultured pearl or imitationNatural pearl, cultured pearl, imitation pearl in glass or plastic: definitions, simple clues such as the tooth test, limits of these methods and the vocabulary used on labels.AuthenticityNatural or heated citrineMost citrines on the market are heated amethyst. What that means, the colour signs, misleading names (topaz, lemon quartz) and the right questions to ask.AuthenticityRose quartz or rose glassNatural rose quartz is translucent to milky; rose glass is clearer and more even. Appearance, bubbles, dyes, misleading names (strawberry quartz) and reliable tests.AuthenticityTreated stones: how to read a labelWhat the words on a stone label mean: natural, treated, heated, dyed, stabilised, reconstituted, synthetic, imitation, and what French law says.AuthenticityBuying stones online safelyWhat a photo does not show, the information to insist on, warning signs, your rights as a remote buyer and the steps to take when the parcel arrives.
The meanings mentioned belong to tradition and symbolism. They are neither promises of results nor medical advice.