Diamond is a precious stone, quality standard, so you should pay close attention to these standards, when you buy a diamond. As for the rest of the gem, it is you and the jeweler to determine their value. There are quite a few gems are synthetic now you should understand what is how to understand them. Ruby, for example, will have a “tagant”, visible, synthetic stone is held under ultraviolet light.
If any of the terms or words, you do not know when, jewelers and you talk, don’t be shy, stop, ask him or her to explain what they mean. If you think the jeweler or business is less than forthcommig or all deceive, leave, get someone else to do business. If you buy expensive stone, then you will get GIA certificate, and take your time when you’re shopping.
There are many types of stones, look very similar, so be aware of what they are. For example, yellow quartz and Huang Shuijing are often mistaken for magnesium and iron garnet and Grossular garnet yellow topaz is very rare and red garnet but they look the same to the untrained eye. If it looks good, then most likely to be true, so don’t jump in hasty transactions need to pay you soon or sight unseen.
At the same time, remember, types of lighting will affect the color stones. See a gem is the best way in normal outdoor lighting. Of course, no jeweler will let you out of the house and a fine piece of jewelry, so they should check for you gems and decent lighting.