Turquoise 101: Treatments, Value And What to Look For
What is Turquoise?
Turquoise is a natural mineral made from copper, aluminum, phosphate, and water. The copper gives it its beautiful blue color, while traces of iron can make it more green. Because it holds a little water inside, turquoise is softer and more delicate than many gemstones — which is part of what makes it so unique.
Turquoise has been treasured for thousands of years and appears in some of the world’s most famous ancient jewelry. In Egypt, artisans used turquoise as early as 3000 BCE, inlaying it into gold collars, amulets, and scarabs. One remarkable example is the pectoral of Pharaoh Senusret II’s daughter, a masterpiece combining turquoise, lapis lazuli, and carnelian in a detailed gold setting. Egyptians also created broad “Usekh” collars with rows of turquoise beads that draped across the chest and shoulders of nobles.
Scarab Ring, Egypt, New Kingdom, 1540–1069 BCE
In Persia, turquoise was equally celebrated. The rich blue stones from the Nishapur mines were used in crowns, ceremonial jewelry, and even to decorate palaces and mosques. Turquoise was believed to bring protection, good fortune, and spiritual strength, making it a powerful symbol as well as a decorative stone.
These historic treasures remind us that turquoise has always been more than a gemstone—it is a cultural icon that has carried meaning, beauty, and prestige for millennia.
Marie Louise Diadem, gifted from Napoleon to his wife.
Arizona Turquoise
One of the most famous U.S. sources of Turquoise is the Kingman Mine (also known as the Mineral Park turquoise mine) in northwest Arizona.
Kingman has a long history: Native Americans worked the area as far back as ~600 A.D., and commercial mining began in the 1880s.
The mine produces a range of colors—from pale blue to deep sky blue, sometimes with greenish tones—and often shows attractive matrix (“webbing”) patterns in black, brown, or white. Blue stones with dark “spiderweb” matrix are especially prized.
Raw Kingman Mine Turquoise, Tucson Gem Show January 2025, Kino Show
Common Treatments
Turquoise is naturally somewhat soft (Mohs ~5–6) and porous, so untreated material can be fragile, chalky, or prone to fading. To improve durability and appearance, several treatment methods are used:
| Treatment | What It Does | How It’s Done / Typical Materials |
|---|---|---|
| Stabilization / Impregnation | Fills pores, hardens the stone, enhances color and durability | Epoxy/acrylic resins or polymers infused under pressure or vacuum |
| Waxing or Oiling | Temporarily improves luster; can slightly deepen color or matrix contrast | Natural or synthetic waxes/oils applied to the surface (less durable) |
| Dyeing | Changes or intensifies color (blue or green) | Colorants added (often with stabilization); may fade over time |
| Compressed / Block / Composite | Creates larger, uniform pieces from small fragments or powder | Bits/dust bonded with resins under heat and pressure |
| Premium Processes (e.g., “Zachery”) | Aims to maintain a more natural look/feel while improving stability | Specialized, lower-visibility treatments identifiable via lab analysis |
Does Treatment Change Value?
Yes. The type and extent of treatment significantly influence value:
- Natural/untreated turquoise with strong color, pleasing or minimal matrix, and good stability generally commands the highest prices.
- Stabilized turquoise is widely accepted, durable for daily wear, and more affordable than comparable untreated high-grade stones.
- Heavily treated, dyed, compressed, or reconstituted material is typically less valuable and less favored by collectors.
What’s the Best Turquoise to Buy?
- Color: vibrant, saturated blue (Kingman’s sky-blue tones are a benchmark) with minimal green/brown if you prefer classic color.
- Matrix: if present, it should add beauty rather than distraction. Thin, even “spiderweb” or “water-web” matrix is highly desirable.
- Structure: solid, less chalky material. If stabilized, look for high-quality, well-executed work.
- Provenance & disclosure: know the mine and any treatments to compare value and trust your purchase.
