If you want to buy Natural Alexandrite Jewelry or pendant, you should be able to distinguish natural from synthetic stones. If you don’t, most likely you will buy synthetic stones, which are cheaper than natural ones. One of the easiest ways to tell them apart is by looking at their color in sunlight and seeing if they have ‘hot’ or ‘cold’ flashes.
Natural alexandrite has a natural oily shine when it’s very hot outside (or when you simply wear it). Under this condition, alexandrite will show a greenish color. When it’s cold outside (or indoor), the stone shows purplish-red color. This is why they call natural alexandrite ‘the chameleon.’ Without sunlight and different temperatures, the stone just looks purple or red and doesn’t change color.
Synthetic stones have the same shine as natural ones, but they are not stone, so they don’t change colors with changes in temperatures. Synthetics also don’t show oily sheen (are not ‘oily’). They look like plastic most of the time without sunlight or if you wear them.