If you’ve been making jewelry for a while, you’ve probably wondered how gemstones get their color.
- What do terms like color enhance really mean?
- Have the stones been dyed, heat-treated, or irradiated?
- Are these treatments common?
- Will it last?
- What do you tell your customer?
If you sell jewelry, you should know the answers so you can inform your customers. Almost all beads are dyed or treated in some way. This is not a problem, but all color will fade if left in the sunlight too long – either dyed or natural stone.
Color enhancement has existed for thousands of years. In ancient times it was common to submerge turquoise in animal or vegetable oil. This formed a long-lasting luster, but with oil stains appearing when worn!
Today, many turquoise beads are color shot or color stabilized. Implying natural color which is stabilized – this is untrue, as color is added. However, there’s nothing wrong, as jewelry making is art and color enhancement improves the appearance.
Dye & bleaching
Ancient Romans’ dyed agates. The process makes your beads more attractive and has few drawbacks. It’s so common, that even if a seller tells you the beads aren’t dyed, they properly are! The dye usually won’t come off, but it’s still best to rinse some stones before using them just in case. Don’t fool yourself, the truth is:
- Almost ALL jade and pearls are dyed (white pearls are bleached).
- Most porous stones like chalcedony and quartz are dyed. Natural chalcedony comes only in pale periwinkle gray.
- Blue topaz and garnet beads are dyed to make them appear more vibrant.
- Almost all coral is dyed, especially red coral.
Heat-treatment is another technique that has been used for thousands of years. Carnelians are heat treated to intensify their orange color, and usually citrine sold today is really heat-treated amethyst. Sapphires and rubies in most fine jewelry are heat-treated as well, although you won’t see many of these stones in bead form.
Many bright colors are formed in stones like diamonds by natural radiation. However, artificial electromagnetic radiation can produce beautiful colors in stones that aren’t even found naturally. Irradiation is a modern way to alter colors of gemstone – commonly used to intensify blue topaz and to create smoky quartz out of ice quartz.
How to Tell Natural Color from Dyed
It’s hard to tell if the color of a stone is natural – but one giveaway of dying is to look closely with a magnifying glass into the bead holes. You may be able to see a different color inside.
Sometimes the dye is uneven with varying density across the strand – resulting in not all the beads being the same shade of color. One other sure way to tell dying is to break the bead open. However, it’s even possible for the inside of a bead to be the same color as outside, yet still be dyed!
Another method to expose dye is to put the beads on a damp white towel. Wait a few minutes to see if the color bleeds on the towel. If there’s noticeable color transferred, there will be a ring of color around the neck of whoever wears the beads in a necklace!
Don’t be too concerned about artificial techniques to improve your beads. It’s much more common than you think, and you’d need a qualified gemologist to tell otherwise. It’s not all bad, the stone’s properties are not altered, and dyes are color-fixed so they won’t come off. Nevertheless, the more you pay: the more natural the stone will be.