Differences Between Natural vs. Stabilized Turquoise
What is the difference?
How turquoise is formed.
Turquoise takes millions of years to form in the earth. Technically, it is a secondary mineral of hydrous aluminum phosphate with a cupric base. It forms when water containing specific minerals gradually filters through alumina-rich crevices and fractures of volcanic rock and then evaporates, forming veins or nuggets. Color varies depending on what chemicals are contained in the water and also oxidization from pre-existing minerals. The presence of copper creates the blue colors that we have come to love with turquoise. If there is more aluminum than copper the turquoise will be more of a green color. Iron, zinc and other minerals can influence color as well, creating a range of colors from white, yellows, apple greens and other neon's.
Turquoise is typically formed in dry arid climates around the world at elevations between 3000 to 8500 feet. At these elevations it makes turquoise a difficult task to mine, dealing either with extreme heat or extreme cold. Most of the famous American mines are now permanently closed, making their turquoise more valuable and sought after for its rarity.
Ideally when seeking out quality turquoise most would choose natural for the finer qualities to be used in higher end jewelry. Natural is defined as nothing has been done to it (no waxes, dyes, resins, or other treatments). However, only 3 to 5 percent of all turquoise mined is a hard high-quality material that does not need any stabilization. That is why natural turquoise is so valued, being more rare and less abundant. The rest is low to medium grade and is soft and chalky, requiring stabilization. So the bulk of turquoise on the market is stabilized. Only a small percentage, if available, is natural. In recent years natural turquoise has been exceedingly harder and harder to get as most of the turquoise was mined years ago and the stock piles are running out. The demand of natural turquoise is becoming more popular as people learn the difference. Most natural turquoise on the market has been undervalued as the stock piles are depleted. Most of the people in the industry who understand natural turquoise are scooping it up as it is diminishing quickly. The price has been increasing every year.
Working Natural Turquoise
Natural turquoise requires some skill to work with. It can have many different degrees of hardness, depending on its matrix and surrounding host rock and chemical composition. It takes some experience to get to know natural turquoise and work with it. Natural turquoise can have pits or natural fractures which adds to the characters of it but can be more difficult to cut. Due to the nature of natural turquoise, parts of the stone can be fragile and require some kind of surface treat in order to preserve it while cutting it. The most common materials used are Paleobond, Starbond, and Opticon as examples of industry standards. The host of the turquoise material can have different densities that need to be strengthened before cutting. There can be fractures created from the different densities of the two materials; so in this case it is still considered natural turquoise . Any ethical Turquoise dealer and jeweler will readily disclose the use of surface treat when needed, meaning if a spot of treat was placed on an edge of fragile matrix for example.
It is also very important to understand how to strengthen turquoise that is natural. It is not uncommon for a large percentage of natural turquoise to be backed. It has been a standard in the industry, but it is not required if it is strong enough. The most common treatment is Devcon which is a material that is applied as a backing to give it strength. We will go into this in the future articles with examples on how to back your turquoise.
Every piece of natural turquoise is different. There are varying degrees of hardness, generally between 5 - 6.5 on the Mohs scale. Color and appearance vary from pale to deep bright colors, and the texture can be shiny, glossy or waxy depending on its chemical make up when polished.
95% - 98% of turquoise mined is too soft to cut, therefore it requires some form of stabilization to be used in jewelry. Stabilization is a process necessary for soft, chalky material to be made into a usable product. The stone is put under pressure for long periods in order for it to absorb resins to enhance its hardness. Stabilized turquoise is sometimes also color enhanced with dyes to improve its color when a chalky stone is too pale. The process of stabilization has saved many a fine stone and it has its place in the turquoise world. Stabilized turquoise is attractive because it is consistent, reliable and easy to work with, if stabilized from a reputable source. Once stabilized, it is no longer porous so it will be strong and maintain its hardness; whereas natural turquoise will change over time from oxidization and exposure to skin oils, soaps, lotions and such. There are many ways turquoise can be stabilized.
Be cautious as there is a lot of inferior stabilization on the market that is poor quality and the turquoise actually still crumbles. Even worse, some stabilized turquoise smells strong of chemicals and is toxic to work with. Stabilizing turquoise correctly is a long process and requires expensive materials to achieve a quality stabilization. If done well, a quality piece of turquoise will be saved and can be created into a usable long lasting gemstone. These are the differences between stabilized and natural turquoise. So depending on your skill level and your price point, now you will have the ability to choose wisely as you purchase your turquoise.