Various deceptive techniques are used to alter the appearance of lesser value gemstones. Often these practices are intended to deceive the consumer. However, all of these techniques are considered legitimate if they are revealed to the buyer. Listed below are a few tricks that every jewelry consumer should be aware of:
- Painting. Using paint or some other colored material underneath a gem to improve its color. For example, a speck of paint placed on one spot of the gemstone will reflect throughout the entire stone.
- Foil Backing. Using foil behind gems adds brilliance to the stone. This technique is often found in jewelry with closed back settings. The use of foil was common and is often seen in antique jewelry.
- Crackling. Cracking synthetic gems by applying thermal shock. This technique if often used on lab-made stone to create the flaws found on natural stones.
- Assembled Stones. Two or more stones are glued together to form a bigger and better looking gem. Several types of composites can be made. Assembled opals are normally disclosed to the consumer and are not considered a deceptive practice. However, this technique is often used with Sapphire or Ruby to deceive the consumer.
It can be difficult to spot a fake stone. Your best defense is to buy jewelry from reputable jewelers. An honest establishment will always reveal to the consumer what treatments a gem has received. As a general rule, a buyer should avoid gems that have been set on a closed backing, unless the item in question is an antique.