The Color of Summer
The color blue is used in jewelery making since ancient times by the Egyptians and the Aztecs. The main sources of Turquoise are Arizona, Australia, Chile, China, and Mexico. The stone often occurs with darker veins, and it tends to turn color. Available colors ranging from sky blue, bluish green, apple green and teal.
- COMPOSITION: CuAl6(PO4)4(OH)8·4H2O
- HARDNESS: 5 - 6
- DENSITY: 2,9
Among the popular products sold per gram in the jewellery there is the COMPOSE TURQUOISE which is obtained by taking as a base powder of turquoise (phosphate hydrate of aluminum and copper) with the addition of the resin. In market there are some variations, in order of value we have: pasta of turquoise 4 flowers (product of jewellery), paste of turquoise 3 flowers, paste of turquoise (product of bijotteria).
STABILIZED TURQUOISE is a product to prevent discoloration of turquoise through the infusion micropores in the natural stone of the resin, hence the name stabilized. Stabilized turquoise from China is the result of the process by which the effect is obtained as dark streaks the natural turquoise, the value is not very high fits into the segment of bijotteria similarly to the paste of turquoise normal.
Another thing is the NEOLITE (value much lower than the paste of turquoise) which is obtained by chemical processes for recycling plastics. Sometimes it is confused, not to say that is improperly sold as paste of turquoise. In fact it is easy to confuse it... a buyer, not expert, could judge better the neolite - the higher specific weight and features highly reflective surface.
Another product of imitation apparently similar to the variety to 4 flowers is a product made of an inner part having a weight specific similar to 4 flowers and an enamel coating turquoise color that some indicate it is surface coating in paste of turquoise. Over time a necklace of this kind will degrade on the surface.