expert answers to common gemstone questions covering quality, authenticity, certification, pricing, treatments, value, and gemstone care tips.
Fake gemstones often give themselves away in a strange way, like having interiors that look too perfect, with an even, uniform colour spread, tiny round gas bubbles sealed in, or a touch that feels noticeably warm, not that usual cold sensation you get from natural stone. Glass and plastic simulants typically do not share the…
You can move a gemstone effectively, first by getting an independent grading report from a well-known lab and then presenting it through auction houses, specialised gem dealers, or vetted online marketplaces.
Natural citrine is usually spotted by its pale, even yellow to brownish-yellow look and the fact that it can show subtle dichroism. Heat-treated amethyst, which is the most common imitation, doesn’t show that feature entirely. Most of the citrine sold out there is actually heated amethyst. It often turns up with a strong, opaque orange…
Genuine turquoise has a natural, irregular matrix with inclusions, a somewhat porous surface too, and a Mohs hardness of 5 to 6, so it ends up clearly tougher than most plastic or resin imitations. One common simulant you will see in the market is dyed howlite, which readily shows a pale interior when scratched or…
You can figure out real jadeite or nephrite by looking at its relatively high specific gravity, noticing how it stays cold in your hand, and seeing an interlocking granular or fibrous crystal structure that you can actually spot when you magnify it. Common fakes like serpentine, aventurine quartz, or dyed glass don’t show jade’s exceptional…
Real alexandrite shows a bold colour-change trick, where it goes from greenish or bluish green in daylight to a purplish red when incandescent light is used; also, it tends to sit around a refractive index of 1.746–1.755. Man-made, colour-change sapphire is frequently marketed as alexandrite, yet the mineral makeup is not the same, and it…
Gemmologists try to sort treated gemstones out by looking very closely for internal stress fractures, altered inclusion structures, dye concentrations that reach up towards the surface via cracks, or colour zoning that looks off when viewed at high magnification. Different kinds of enhancements tend to leave specific forensic clues. Heat treatment in sapphires, for instance,…
Natural sapphires can be checked by spotting angular colour zoning, hexagonal growth lines, or real mineral inclusions such as intersecting rutile silk when viewed under 10x magnification. Since sapphires share the same corundum crystal structure as rubies, the identification methods overlap quite a bit. When you see straight, sharply angled colour bands, that is a…
Genuine rubies are usually recognised by their kind of silky inclusions, rutile needles, plus a bright red fluorescence when you shine long-wave UV light, and also by a high refractive index that sits around 1.762 to 1.770. If you look through a jeweller’s loupe, a natural ruby will commonly show intersecting needle-like features or other…
A real emerald is usually recognised from its special jardin, meaning internal inclusions, then from a certain refractive index that sits roughly between 1.577 and 1.583, and also from how it reacts with a Chelsea filter, where it often shows up as pink or red, not always, but frequently. Natural emeralds seldom have perfect clarity;…