Reconstituted Turquoise
Reconstituted Turquoise
Bonded turquoise powder pressed into block material for inexpensive jewellery
Reconstituted turquoise is a composite material made by mixing powdered turquoise or fine fragments with a resin or epoxy binder and compressing the mixture into solid blocks. The resulting stock is sliced and cut into beads, inlay strips, and cabochons, almost exclusively for the lower price segments of the silver-jewellery, costume, and souvenir trades. Trade names include block turquoise, compressed turquoise, and the loose and slightly misleading chalk turquoise. All require disclosure under FTC, CIBJO, and AGTA guidelines, and recognised laboratories report reconstituted turquoise separately from natural and stabilised material.
Composition and manufacture
The starting material is generally low-grade or chalky turquoise — porous, soft, often pale or unevenly coloured stock that is not commercially viable in solid form. The rough is reduced to powder, blended with epoxy or polyester resin, and pressed under heat and pressure into blocks or rods. Pigment is typically added to deepen colour to the saleable blue or blue-green ranges, and bronze-coloured powders or epoxies are sometimes added to imitate the matrix patterns of higher-grade material. Binder content varies widely, generally between 10 and 30 percent of the finished mass, with the higher-binder products approaching the boundary between reconstituted material and outright imitation.
Reconstituted turquoise differs from stabilised turquoise in a fundamental way. Stabilisation impregnates a solid piece of natural turquoise rough with a polymer to harden it without altering the underlying structure; the original colour and matrix pattern remain in their natural arrangement, and the treatment improves the workability of porous or fragile stock. Reconstitution destroys the original structure of the rough by powdering it, then bonds the powder into new shapes; the resulting material has no natural structure at all. Stabilisation is widely accepted in the trade as a routine treatment when disclosed; reconstitution is treated as a separate, lower-value category.
Specific gravity of reconstituted turquoise is typically 2.0 to 2.5, against 2.6 to 2.9 for natural turquoise, the difference reflecting the resin content and the porosity of the starting material. Hardness is markedly lower than natural turquoise — typically 3 to 4 on the Mohs scale, against 5 to 6 for natural — because the binder is the weakest component. The polished surface has a waxy or plastic appearance rather than the vitreous polish of fine natural turquoise.
Identification
Trained gemmologists distinguish reconstituted turquoise from natural and stabilised material by several diagnostic features. Magnification reveals a granular, homogeneous structure with visible particle boundaries, binder pockets, and the absence of the natural turquoise micro-structure. Specific gravity is lower than the 2.6 to 2.9 typical of natural turquoise. Hot-point testing produces a resin odour. Fourier-transform infrared spectroscopy provides definitive identification of polymer content and is the reference method in modern laboratory practice. Matrix patterns, when present, frequently appear suspiciously regular or are visibly created from added bronze powder rather than veins of natural host rock.
The trade also encounters fully synthetic and imitation turquoise made from dyed howlite, dyed magnesite, plastic, glass, or bonded calcite, none of which contains genuine turquoise. These are not reconstituted in the strict sense; they are imitation materials. The combination of widespread dyed howlite, reconstituted material, and fine stabilised turquoise in the same price range makes the lower turquoise market one of the more confused segments of the coloured-stone trade. Buyers who want assurance of natural origin in the absence of laboratory documentation should be sceptical of all material in the lowest price ranges.
In the trade
Solid natural turquoise from Iran, the American Southwest, China, and other historical sources commands prices ranging from modest to substantial depending on colour, matrix, and source. Persian (Iranian) Nishapur material remains the historical reference for fine sky-blue turquoise; American Southwestern material from Sleeping Beauty, Bisbee, Lone Mountain, and other named mines is highly collected. Stabilised material of comparable colour trades at a discount but is still a recognisable mid-market category. Reconstituted turquoise sells at a small fraction of either, typically in inexpensive bead strands, machine-cut cabochons, and decorative items. Disclosure should identify the material as reconstituted, and where dye has been used, as dyed reconstituted.
For Native American silver jewellery and the higher end of the turquoise trade, only solid natural or properly stabilised material is acceptable. Reconstituted turquoise misrepresented as natural is a recurring problem in tourist and online markets, and laboratory verification is the only reliable safeguard for significant purchases. The Indian Arts and Crafts Act in the United States provides additional protection against misrepresentation in the Native American jewellery sector, but enforcement focuses on the broader question of authentic Native American manufacture rather than on turquoise treatment per se.
Care
Reconstituted turquoise is softer and less stable than natural or stabilised material, and the resin binder is vulnerable to heat, ultraviolet exposure, and solvents including perfume, hairspray, acetone, and strong cleaners. Ultrasonic and steam cleaning are not recommended. Clean with a soft cloth and mild soapy water, dry promptly, and store away from heat and direct sunlight. Avoid prolonged contact with skin oils and cosmetics, which can yellow or degrade the binder over time. The polished surface dulls faster than natural turquoise under normal wear and is difficult to restore by re-polishing because the resin softens under polishing heat.