All of the stones, with the exception of some of the acrylic stones and the Chinese crystal, are vintage stones. These stones can be dated from as far back as the early 1900's to the 1970's. The color of the stones may vary slightly from year to year. When filling orders we try to make sure that all of the stones are the same shade. However, there are occasions when we are low on stones and will have to fill the order with the stones on hand whether they are all the same shade or not. Some of the foil back stones may have bad foil. We try to catch this and note it in the description. If the foil is damaged on the stones you can always remove the foil by soaking them in salt and vinegar.