On the other hand, a calcium rich sea shell can form into turquoise if it happened to fossilize near a copper vein in the arid American southwest. Synthetic plastic turquoise that has been dyed blue and machine molded can be mass-produced and has little value. The fragments and impurities of the host stone that are not transformed into turquoise create a matrix of lovely unique colors and patterns. Physical structure makes up 55 points: Hardness (20), Enhancement (20), Composition (10), and Cut (5). The resulting stoneвЂ™s physical properties are key indicators that help determine the value of the stone. Some turquoise is not formed completely and needs the aid of enhancing agents to make it usable in jewelry. The combination of different elements in the host rock material can change the appearance and structural integrity.

In an arid environment, turquoise forms inside the earth withinВ host rocks (such as limestone and sandstone) under and high temperature and pressure, making it as hard as glass. Chemically, itВ is a hydrated aluminum copper phosphate.

Turquoise is a beautiful, hard, opaque, triclinic cryptocrystalline stone found in shades of green and blue. For better accuracy please consult with a turquoise expert. There is usually a slight deviation depending on the person scoring the TQI. This is only a guide to make evaluating the price of turquoise easier. Also, the availability of turquoiseВ tends to fluctuate respectiveВ the production levels of operating mines. Most of these indicators are widely agreed upon however, color, clarity, and stone pattern have been a subject of dispute.В It may beВ hard to get an exact number because of the subjectiveness of these qualities. These componentsВ are broken down into 8 indicators and weighted according toВ importance.В Determining the TQI is a process of scoring these 8В indicators. These are the stoneвЂ™s physical structure and the stoneвЂ™s rarity. There are two major components that can be evaluated that contribute the true turquoise value. The TQI scoring system is a great way to get a quick estimate. High numbers are rare less than 1% of turquoise on the market score a 90 or better. The higher the TQI number, the better quality the turquoise, the higher the grade and the more valuable the stone. The TQI is a number on a scale between 8 and 100. The Turquoise Quality Index (TQI) is a measurement of the quality of the turquoise stone. This price can range from $0.05 to $500 per carat, depending on the stone. So the first step is to weigh the stone, and then figure out what the price is per carat. It is common to see turquoise priced per carat when it is for sale. The heavier the stone, the more valuable it is. Turquoise is weighed in carats, where 5 carats equals 1 gram.

Turquoise Price = Weight (Carat) X Turquoise Quality Price/Carat Index (TQI) The weight of the stone andВ the Turquoise Quality Index can help us determine how muchВ a stone is really worth. There are many factors in play that determine a stoneвЂ™s price, some are subjective and others tend to change over time. TheВ difference between quality turquoise and cheaper stones can be a little confusing. The price of turquoise stones normally range from $1 to $10 per carat but can range fromВ $0.05 to $1000 per carat depending on the quality. What is the valueВ of your turquoise stone? How much a turquoise stone is worth is a common questionВ among turquoise collectors.

Onyx 10.10.5