The composition and structure of synthetic crystal are exactly the same as those of natural crystal. Especially when the interior of the crystal is very clean and no features can be seen, even laboratory identification becomes quite difficult and large-scale instruments must be relied on. In this situation, it is very difficult to distinguish between natural and synthetic crystals only by the naked eye and portable instruments such as a tenfold magnifying glass. However, there is also a less effective method, which is to place the crystal to be tested at room temperature until its temperature stabilizes, and then feel the degree of its coldness with your hand. Generally speaking, natural crystal is cooler, while synthetic crystal or glass has a warm sensation. However, this method is greatly influenced by weather and environment and is not applicable in winter. Moreover, because individuals have different perceptions of temperature, it is only an auxiliary identification method.
However, most natural crystals contain more or less inclusions, which experts often refer to as cotton, streaks, clouds and mists, mineral inclusions, etc., forming varieties such as green ghosts and various lustrous crystals, presenting a scene full of vitality. Synthetic crystals, on the other hand, are relatively clean, but sometimes they also exhibit certain characteristics. If any of the following characteristics occur, it can be determined as synthetic crystal:
(1) A glass tabletop that has not been wiped for a period of time will accumulate a layer of dust. I'm sure everyone has witnessed this phenomenon. If you observe a phenomenon similar to "table dust" inside a crystal, it means that there are many very tiny gray or white dots distributed along one or several parallel planes in the crystal, while the rest of the crystal is very clean. So basically, this is synthetic crystal.
(2) Sometimes in synthetic crystals, there are some very fine hollow tubular inclusions. These hollow tubes are basically parallel and sometimes extend to the surface. They may also be larger at one end and smaller at the other, resembling nails. This is only found in synthetic crystals. It might be some residual fluxes from the synthesis process.
(3) Natural crystals are basically not green, or in other words, extremely rare. Varieties like Green Ghost and Green Hair crystal have green inclusions inside, but the crystal itself remains colorless and transparent. So the large number of green and transparent crystals that appear in the market are basically processed in color, and most of them are synthetic crystals themselves. Counterfeit glass is very cheap and can come in various colors. Sometimes it can even be made semi-transparent, making it relatively easier to identify.