Turquoise imitations fall into two categories: materials that are not turquoise at all — howlite, magnesite, glass, plastic, and Gilson synthetic — and forms made from real turquoise material that has been so heavily processed it no longer qualifies as natural stone, such as blocked and reconstituted stone. Understanding the distinction matters because each type requires different documentation and carries a different market value.
The imitation market exists because turquoise is scarce and expensive at the top end, and the visual effect is easy to approximate. Chambless explains the underlying hardness problem: "Turquoise is relatively soft, and it is estimated that at least 80 percent of it is too soft to cut successfully for jewelry without having the stone cracking, losing luster, or changing color." (~line 10500–10515.) When most natural turquoise cannot be used without treatment, and gem-grade natural turquoise commands high prices, the market pressure toward substitution and imitation is structural.
The most common non-turquoise substitute is howlite — a white mineral that dyes easily to a convincing blue-green. Lowry documents it directly: howlite is a "white mineral, dyed blue/green; commonly sold as turquoise." Magnesite is a similar mineral used the same way. Neither has any relationship to turquoise mineralogically; dye is the only connection.
On the processed-turquoise end, blocked and reconstituted stone represent opposite ends of a spectrum. Blocked stone is produced by compressing turquoise crumbs under high pressure — some mineral fragments remain, but the natural structure is destroyed. Reconstituted stone goes further: the turquoise is powdered completely and mixed with a binder to form a solid block. Reconstituted material contains real turquoise powder, but it is not natural turquoise by any standard definition.
The most technically sophisticated imitation is the Gilson synthetic. Lowry: "In the 1970s, he [Pierre Gilson] developed a synthetic turquoise that was said to be mineralogically identical in every way to natural turquoise. This process produced an imitation to the clarity and robin's-egg blue color of Persian turquoise." (~line 9990–10040.) A black matrix version was subsequently added. Lowry's careful phrase — "said to be mineralogically identical" — signals that the claim is commercially reported, not independently verified in his account. Gemological testing distinguishes Gilson synthetic from natural turquoise in laboratory settings, but not reliably by eye.
Glass and plastic imitations are the lowest-cost and most easily identified substitutes. Both appear in Lowry's account of the imitation spectrum. In period jewelry, glass trade beads imitating turquoise are documented alongside genuine turquoise beads — a collector caution that applies to historic as well as contemporary pieces.
For treatment taxonomy (stabilized, Zachery, fracture-sealed — materials that are still turquoise), see Natural vs. Stabilized Turquoise. Browse verified material sourcing in the Silversmith Directory.
Q: What is the difference between imitation turquoise and fake turquoise?
Imitation turquoise includes materials that are not turquoise at all — howlite, magnesite, glass, plastic, and Gilson synthetic. Reconstituted and block stone are made from real turquoise material but so heavily processed they no longer qualify as natural. The distinction matters for value and required documentation.
Q: How can you tell if turquoise is real or howlite?
Howlite and magnesite are white or gray minerals that absorb dye readily and are widely sold dyed blue to resemble turquoise. A scratch test on an inconspicuous edge, acetone test on the dye, or professional spectrometer analysis can distinguish dyed howlite from natural turquoise. Visual inspection alone is often insufficient.
Q: What is stabilized turquoise?
Stabilized turquoise is genuine turquoise that has been injected with a polymer resin to harden soft or chalky material, allowing it to be cut and polished. It is still real turquoise, but the treatment must be disclosed. Stabilized stone is generally less valuable than natural, untreated stone of comparable color and hardness.
Q: What is block turquoise?
Block turquoise (also called reconstituted turquoise) is made by grinding turquoise powder and binding it with resin or epoxy under pressure. Unlike stabilized turquoise, it contains no intact stone and is essentially a composite. It carries the lowest value of the turquoise-derived materials.