Article in English: Lab-created sapphires are essentially glass that is put through a process similar to the one that forms natural sapphires. Since they are glass, tiny air bubbles remain in them after they form. If you see any bubbles inside of the sapphire then it is not real. Be sure to turn the sapphire over and inspect it from every angle. It’s possible that air bubbles will only be visible from one angle. If you have two sapphires and you know for sure one is real, use it to scratch the second one. Gems of equal hardness can’t scratch each other, so if both are real sapphires then nothing will happen. If the real sapphire leaves a scratch on the second sapphire, then the second one is not real, or is at least of lower quality. This test can damage a synthetic sapphire, so be wary of ruining the inferior gem. Turn the lights off in a room and shine a flashlight on the sapphire. If the sapphire is real, it will only reflect light that is the same color as the sapphire. If it is fake, meaning it is made of glass, it will reflect other colors besides the color of the gem.

Summary in Chinese:
检查宝石里是否有气泡。 刮刻测试法。 观察光线在蓝宝石上的反射效果。