Genuine Turquoise Cabochons
Turquoise was originally discovered in the Al-Mirsah-Kuh Mountains of Iran. It soon taken to Turkey by way of Europe, then in the 17th century it was named from French "turques" or "turquois" meaning "Turkish". With a hardness of 5-6 on the Mohs scale, making it easy to carve, it soon became a popular stone for jewelry.
The color of Turquoise can range from: Bright Blue, Sky-Blue, Pale Green, Blue-Green, Turquoise-Blue, Apple-Green, to Green-Gray.
Since Turquoise is a softer stone, most jewelry and beads have been enhanced and stabilized by applying intense pressure, filling in natural gaps with plastic filler or epoxy, creating a stronger and harder stone.
Chalk Turquoise is a form of natural Turquoise that has a white chalk-like consistency. It has the same chemical composition as turquoise, only without the Copper (it's the Copper that causes the blue turquoise color). Chalk Turquoise is also softer than regular Turquoise.