How does chalk turquoise differ from "regular" turquoise? Is it manmade and if so, how? Is it less valuable than other types of turquoise?
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 a bit softer than regular turquoise. It is dyed pleasing colors and stabilized with resin to produce beads that are hard enough to use in jewelry. Chalk turquoise is considered less valuable than regular turquoise because it does not contain the minerals that create the rich blue and green colors.
Many people are of the understanding that chalk turquoise comes from the grinding of unusable chips of turquoise left over from cutting beads. This type of bead is actually called ''reconstituted turquoise.'' The left over turquoise pieces are ground into a powder, or chalk, then mixed with resin and formed into sturdy shapes that can be used as beads. By using the turquoise chips for this process, reconstituted turquoise is very affordable to use in everyday jewelry designs.