What is a Doublet or Triplet in Jewelry Making?

A doublet is a gemstone composed of two or three parts- gemstone material in combination with other, less expensive materials or gemstones. Doublets (and triplets) are a man-made ""sandwich" of gemstone slices. Usually the crown is natural stone material while the bottom is composed of less expensive stones. I have seen impressive stone effects where the layers magnify colors and luster of the stones. Using doublets allow me to keep   the prices reasonable and the impact high! I do not use doublets as a substitute for real stones, I use them for creative effect. 

There are creative combinations like the necklace below- a base of turquoise and a crown of crystal that looks intense and glossy, a modern look of turquoise that still retains some of its rustic feel. 

There are many new effects being shown to jewelry designers. I recently purchased some lapis, labradorite and crystal triplets for necklaces and rings- unusual colors with lots of impact. See them here

Historically,doublets were most often used for opals, since opal is both expensive and fragile. Fixing a slice of opal to a black backing causes the color to become more vibrant. Opal doublets are well regarded and a less expensive alternative to solid opals. You can enjoy the look of opal without the high cost.