Fake Diamond Names: Moissanite, CZ and Rhinestones

Fake diamond names describe materials: cubic zirconia, moissanite, YAG, GGG and strass glass. Each carries one number diamond does not, starting with density.

The Names on a Tag and the Material Under Each One

Every name in the left column is glass or a laboratory grown oxide, and none of them is carbon. Marketing names travel between materials, which is why the column that matters is the second one. Diamonique was a yttrium aluminium garnet trade name before it became a cubic zirconia trade name at QVC, and the word on the tag never changed.

Two names in that table get confused with each other constantly. Cubic zirconia is zirconium dioxide grown in a furnace and it has no natural counterpart in jewellery. Zircon is zirconium silicate, a mineral dug out of the ground, and the colourless variety is a diamond imitation with a completely different set of numbers. A seller who writes zircon when they mean cubic zirconia is usually careless rather than dishonest. The density test separates the two in one weighing: 4.60 to 4.80 g/cm3 for zircon against 5.60 to 6.00 for cubic zirconia.

Three of these materials were the market leader in their decade and then vanished. Geology.com dates strontium titanate from the 1950s to the 1970s, and YAG and GGG both lost the trade to cubic zirconia once skull crucible growth made it cheap in 1976. That history matters when somebody inherits a ring. A stone that reads 7.08 g/cm3 is a 1970s imitation, not a modern copy, and the piece it sits in is probably period jewellery worth keeping.

Two names in the table are not imitations at all in the strict sense. White sapphire and white topaz are mined stones sold under their own names. A jeweller who sets colourless sapphire and calls it colourless sapphire has sold you exactly what it is. They land in this list because buyers meet them in settings that copy diamond engagement rings. The measured checks that separate them from diamond are the ones in the full guide to telling a diamond from a simulant.

What a Seller Is Required To Call It

Federal rules give a seller three ways to describe a stone that is not mined diamond, and all three sit in front of the stone name rather than after it. 16 CFR 23.25(b) covers the name of any precious or semi-precious stone. Used for a laboratory-grown, synthetic, imitation or simulated product, that name must be immediately preceded, with equal conspicuousness, by one of five words: laboratory-grown, laboratory-created, manufacturer-name-created, imitation or simulated. Equal conspicuousness is the part sellers drop. A listing that puts DIAMOND in the title and simulated in eight point grey at the bottom has not met the rule.

The same section carries a note that settles a common piece of copywriting. The word faux does not adequately disclose that a stone was not mined. Neither does a jeweller’s own coinage, and neither does a trade name on its own, because Diamonique and Fabulite tell a shopper nothing about carbon.

The definition doing the work sits one section earlier. 16 CFR 23.12(a) defines a diamond as a mineral consisting essentially of pure carbon crystallized in the isometric system. Paragraph (b) of the same section adds a second condition that almost nobody quotes. The unqualified word diamond may not describe an object fashioned with fewer than seventeen polished facets. A single cut carries 17 or 18 facets and a full round brilliant carries 57 or 58. The rule bites on rough and on coarse native cuts rather than on modern goods.

A third section closes the loop on adjectives. 16 CFR 23.27 makes it deceptive to use real, genuine, natural, precious or semi-precious to describe any product manufactured or produced artificially. That covers cubic zirconia sold as a real stone and moissanite sold as a genuine gem, both of which appear in marketplace listings every week.

Four things to read on a listing before you bid:

1. The qualifier and where it sits. It belongs immediately in front of the stone name at the same size and weight as the stone name. In front, not after, and not in a specification table further down.
2. The material word, not the brand word. A trade name is not a material. Ask which of the eleven materials in the table the seller is shipping, and get the answer in writing before payment.
3. Width and weight together. Ask for the millimetre measurement across the girdle and the carat weight. A 6.5 mm round brilliant is 1.00 ct in diamond, about 1.65 ct in cubic zirconia and about 0.92 ct in moissanite.
4. The marks inside the mount. A centre stone worth a laboratory report sits in marked precious metal. Reading a fineness stamp takes ten seconds with a loupe and the method is the same one used for checking whether gold is real.

Retail practice shows what compliance looks like when a company decides to follow the rule. QVC lists its own house material as Diamonique simulated diamond, with the qualifier in the product title rather than buried in the description. That is the format to compare a marketplace listing against, and the gap is usually obvious within a few seconds.

Lab-Grown Diamond Is Not a Fake Diamond

A laboratory-grown diamond is diamond. It is carbon in the isometric system, it reads 3.52 g/cm3 on a displacement test, it sits at Mohs 10, it refracts at 2.417 and it shows no doubling at any angle. Every measured check on this page passes it, because there is nothing in the material to catch. Separating a grown diamond from a mined one needs fluorescence and phosphorescence screening of a kind that laboratories run, not a loupe on a kitchen table.

The rules treat the two categories differently for that reason. Section 23.25(c) allows laboratory-grown, laboratory-created and manufacturer-name-created in front of a natural stone name only when the product has essentially the same optical, physical and chemical properties as the stone named. Cubic zirconia does not, so a listing that calls cubic zirconia a lab-grown diamond is wrong twice: wrong on the material and wrong on the qualifier it chose. Section 23.12(c) permits the word cultured for a grown diamond on one condition. A disclosure such as laboratory-created or laboratory-grown must sit immediately beside it, because cultured on its own reads as an origin claim.

The practical consequence is a price question rather than an authenticity question. A grown diamond and a mined diamond of the same weight, colour and clarity are the same material at different prices. A report from a laboratory states which one is in the box. A simulant is a different material at a fraction of the price of either, and the numbers in the specification cards on this page find it in a few minutes.

Where To Get a Stone Named Rather Than Guessed

Four routes exist and they cost different amounts of money and certainty. A graded report from a gemmological laboratory names the material and records weight, measurements and clarity, which is the only document that ties a number to an object. A bench jeweller with a refractometer and a combination tester will name most of the eleven materials in ten minutes. The combination unit matters, because a thermal-only probe reads moissanite as diamond. GIA reported that behaviour in 1997 when synthetic moissanite reached the market, and the cheap testers still sold today have the same weakness.

A 0.001 g scale and a set of callipers at home will do more than most people expect. Density alone separates cubic zirconia, GGG, white sapphire and zircon from diamond. The water displacement method used here also works on pearls and on precious metal. The limits are honest: the method needs the stone out of its setting, and spinel and topaz sit close enough to diamond that the scale gives a lean rather than an answer.

Legitly sits before all of that rather than in place of it. It reads the stone and the mount from photographs, flags the wide colour spread that points at moissanite or strontium titanate, and reads the marks inside the shank. It does not name the material and it is not a certificate, and a stone that clears the photo stage still needs the scale or the bench. Other guides in the jewellery section cover the metal side of the same question.

Verdict: Which Name Should Stop the Sale

Stop the sale when the qualifier is missing, when it sits after the stone name, or when it is smaller than the stone name. That is the cheapest check on this page and it needs no instruments. A seller who has read the rule puts imitation or simulated in the title. A seller who has not is either careless about the law or relying on you not knowing it.

Walk away when two measurements fall outside the diamond band. One reading can be your technique. A stone that weighs 1.65 ct at 6.5 mm and also throws colour in sheets is cubic zirconia, and no third test is needed. A stone that doubles its back facet lines at 10x and reads 3.22 g/cm3 is moissanite, whatever the listing said.

Keep the stone and ask a question when the name is honest and the numbers agree with it. Colourless sapphire that reads 4.01 g/cm3, and a tag that says colourless sapphire, is a correctly described piece of jewellery. The problem this page solves is not the existence of simulants. It is sellers using a name that does not match what is in the box. Every entry in the diamond guides works the same way: get the number, then compare it with the claim.