Growth or Treatment: Magnification is the only thing you need to properly identify synthetic moissanite. Forget those testers as they are not 100% reliable. As long as synthetic moissanite is being produced as a double refractive gem material the 10x loupe will be all you need. Notice the images below and you will see why. If you turn the stone so about a 45 degree angle from the table and girdle you will be seeing directly through the bezel facet of the moissanite. If you take just a bit of time to look through that facet onto the facet junctions of the pavilion of the stone, you will see a very remarkable doubling of the facet junctions at that point. This doubling of the facet junctions is diagnostic for synthetic moissanite based on two issues: #1. Zircon has a far higher level of double refraction of the facet junctions, and the colors will not be the colorless to slightly greenish of synthetic moissanite. #2. Synthetic moissanite is a very good imitation of a diamond in brilliance, far more than anything else on the market except cubic zirconia. But since synthetic moissanite is double refractive which excludes CZ. So if you turn the stone on its 45 degree angle and look at the back facets through the bezel facet of the crown, you will see the doubling of the facet junctions of synthetic moissanite.
Secondary Tests: We do not recommend the use of an electronic tester for anything other than a secondary test. We have far too many cases on record of a “Moissanite Tester” giving an erroneous reading and making a jeweler believe that they have a diamond when in fact it is a synthetic moissanite giving an anomalous reading. These testers are marketed beautifully as diagnostic tools, but are known to give error readings in enough cases to establish that they are not reliable. What is most important on this issue is that you do not need the tester with the magnification inspection available. The doubling of the facet junctions as seen through the bezel facet is diagnostic and a test that can be done anywhere without the need for a tester. You just need to get yourself a known synthetic moissanite to practice on to know where and how to look.
Repair and Setting: No special precautions other than care during heating. Stone may turn a greenish color upon heating, but will return to normal color after cooling. Best to remove for retipping and no heating sinking is recommended if leaving set during repairs.