Buy from sellers whose business is specimens, not decor, and put your checking into the name on the label. Manufactured stone is concentrated at the expensive end of the trade.
The piece in my collection that looks least real is a vanadinite. Deep red-orange six-sided prisms standing on a pale grey rock, several of them with faces regular enough that from across a room the whole thing reads as something turned on a machine.
The Handbook of Mineralogy gives vanadinite as Pb5(VO4)3Cl, a lead chlorovanadate that grows “typically in well-developed hexagonal prismatic crystals”, and it names Mibladen in Morocco among the places the large ones come from. The Handbook also prints a measured density of 6.88. Ordinary soda-lime glass sits at about 2.5. Pick the piece up and the weight has already answered the question the eye was still working on.
The reflex the specimen triggers is aimed the wrong way, and it is a reflex I have had myself often enough to say it out loud. A crystal that looks manufactured is usually a crystal that grew, because somebody imitating a stone imitates the appearance of a stone, and the appearance of a stone is lumpy and unremarkable.
The economics of a convincing fake
If you were going to fake a mineral, the sums would have to work before anything else did.
Making something convincing carries costs that do not fall away when the target is cheap. Raw material, energy, a mould or a dye bath, labour, packaging, and a route to a buyer. That floor sits roughly where it sits whatever is being imitated, which means substitution earns its keep when the thing being imitated sells for a good deal more than the floor. Expensive per gram, small, scarce enough that supply cannot simply be increased. Those are the conditions.
Cheap manufactured material does exist on crystal shelves, and some of it is sold honestly as what it is. What happens rarely is somebody engineering a convincing counterfeit of a stone that retails for the price of a takeaway, because the arithmetic will not carry it.
The rules aimed at this sit one trade over. The Federal Trade Commission’s jewellery guides say, at 16 CFR 23.27, that “It is unfair or deceptive to use the word ‘real,’ ‘genuine,’ ‘natural,’ ‘precious,’ ‘semi-precious,’ or similar terms to describe any industry product that is manufactured or produced artificially.” Those guides are not themselves law; they set out what the Commission treats as deceptive under the FTC Act, and the bulk of them is about precious metals rather than stones. The gemstone sections that do exist are built around diamond, ruby, sapphire and emerald, which is where the money has always been, though the rules on disclosing treatments and on misusing a varietal name apply to any gemstone, aventurine included.
What you are exposed to at the cheap end, then, is a stone that is entirely genuine and is being sold under a name belonging to something else, or with something done to it that nobody mentioned. That second half we have handled separately.
Four counters, four different businesses
Across a collection built since 2008 I have bought from four kinds of seller, and what I have learned from it concerns sellers more than stones. The accuracy of a label is predicted by what the seller’s business is, and that is settled before you look at any particular piece. Choose the counter and you have made most of the decision.
- A collector-grade specimen dealer sells minerals to people who care which mineral it is. Locality tends to travel with the piece because the customers ask, and species names are used carefully because getting one wrong costs the dealer a reputation. This is where I bought the vanadinite.
- At a rock and gem show you get many sellers in one room, sometimes importers and occasionally the people who dug the material. Comparing forty of the same thing in an afternoon is the fastest way to learn what ordinary looks like. Ask two neighbouring tables the same question about the same stone and the answers themselves tell you something.
- Your local crystal shop sells the practice as much as the mineral. The good ones are excellent, and their real value is that you can handle everything. Naming is more variable here, because the supplier’s label is often the whole source of the name, and the chain behind it had no particular reason to check.
- Marketplaces sell listings. Every kind of seller above trades through them, and so does everybody else, and nothing about a platform separates the two. What you are judging there is a particular seller rather than a channel.
Three of the four are places I buy from regularly, so read that as a map rather than a ranking. The same question gets a different quality of answer at each counter, and knowing which counter you are at tells you how much weight to put on what you are told.
Checking the name instead of the stone
Ask what the mineral is called, and notice whether the answer arrives without a glance at the label. A seller who can say what a stone is, and what it tends to get confused with, is a seller whose supplier was asked something at some point.
What was done to it is the next thing to establish. Expect “nothing I was told about” rather than a guarantee, because that is the shape an honest answer takes at most counters, and a shop that gives it in those words has decided not to guess on your behalf.
Handling the piece is the last part, and it comes with a caveat about what it can settle. Heft against size answers the cases where the substitute is much lighter than the mineral, which is how the vanadinite answers for itself. It will not separate glass from quartz, because the two sit within a few percent of each other and a hand cannot read that. The surface tells you something as well. Ground and polished material carries small irregularities along its edges that a mould does not reproduce.
None of that is glamorous, and it is most of what protects you. Real turns out to be a property of where you bought the thing and of what the person selling it was able to tell you, rather than anything the eye can settle on its own. When a name does come back and you want to know whether it belongs to a mineral or to a marketing department, the Crystalance Mineral Library has an entry for the one and nothing at all for the other.
Sources
- Handbook of Mineralogy, vanadinite, for the formula, the hexagonal habit, the measured density and the Mibladen occurrence: handbookofmineralogy.org
- 16 CFR 23.27, Federal Trade Commission Guides for the Jewelry, Precious Metals, and Pewter Industries, on the misuse of “real”, “genuine” and “natural”, and 16 CFR 23.0 for the status and scope of the guides: ecfr.gov
