The turquoise, stone of the month of December. Find out why to sell turquoise stone is very common in China and also find out why turquoise can be easily altered and how it should be cleaned and stored.

It is the stone that, according to tradition, accompanies the month of December. But turquoise has an even older history than the (recent) custom of combining a stone for each month of the year. In fact, turquoise has been used since antiquity as a precious and ornamental stone.

All about sell turquoise stone

The oldest turquoise is the one used for a bracelet that dates back to about 8000 years ago, discovered in Egypt. And another jewel with turquoise was found in the sarcophagus of a mummy of 7,500 years ago.
The blue stone was also used by the Aztecs, the Maya and the Incas, as well as among the Native Americans. It was also known to the ancient Romans: it was used for a bust of Emperor Tiberio, preserved at the Silver Museum of Florence. Other turquoise stones are found in the Treasure of San Marco, in Venice.

Why is turquoise called this? Simple: the word comes from the French term to indicate Turkey. In fact, the mineral was introduced to Europe via Turkey, from mines in the province of Khorasan, in Persia. The first use of the word turquoise to indicate the stone is from 1573.

Where is it? Turquoise is usually found in arid regions, in filler cavities, often with associated limonite and other iron oxides. The largest production is located in Iran, Egypt (Sinai), United States.

Turquoise is a blue-green mineral. It is opaque, with a uniform blue colour or some brown or black dendritic veins of limonite. It is very rare in the form of transparent crystals. Its porosity often causes alterations to the original colour. The turquoise reaches a maximum hardness of 6 on the Moh scale (the diamond is at 10). In practice, it is slightly harder than a window pane. The colour is variable: from white to sky blue, up to the yellowish green.

The most used cut is cabochon, ie with a curved surface without facets.

Turquoise care

Since it is a medium hard stone, turquoise is usually treated to improve colour and strength. Attention, therefore, because it is difficult to provide all the information to those who buy a jewel with turquoise. For example, turquoise is often subjected to waxing and oiling, to improve colour and shine. This is a traditional and generally accepted treatment. However, oiled and waxed stones tend to “sweat” if they are exposed to the sun or to a source of heat. In this case, they can develop a film or a white patina.

In that case, it is better to bring the jewel back to an expert who can make the stone bright again. But there are also turquoises treated with plastic or glass. This process consists of impregnating under pressure the chalky material, an epoxy and plastic resin (such as polystyrene) and glass powder (sodium silicate). Plastic and glass water treatments are much more durable and stable than wax and lubrication. But it is a non-natural method, which is rejected by many. Most of the turquoises in the United States are treated with this method. There is still an even stronger method: using Prussian blue or other dyes. Obviously in this way the stone is even more altered than its natural state.