Man-made spinel is used extensively. Discovered accidentally when scientists were experimenting to try and produce a flame-fusion blue synthetic sapphire, spinel’s great advantage is that it can be made to reproduce almost all colors except purple. The blue synthetic spinel sapphire imitant is much more genuine looking than a synthetic blue spinels imitating synthetic sapphires.
Although synthetic spinel is also produced by flame-fusion, any resemblance between man-made spinel versus Verneuil rubies and sapphires or other colored corundums ends at the torch. You’ll seldom see bubbles or curved striae in man-made spinel regardless of age.
Some of the imitations using man-made spinel do contain clues, though. An imitation Lapis Lazuli is made by sintering finely ground synthetic spinel and then recompacting it under pressure. Sometimes, real gold is included in the product to simulate the pyrite (fool’s gold) so characteristic of natural Lapis. You can generally spot this imitation because of intensity of the color, and because this color contains an inappropriate reddish influence.
Compare the imitation, too with natural Lapis and you’ll see that the luster of the imitation is much too high.
A very authentic looking moonstone imitation is also possible with man-made spinel. Colorless material is reheated long…