Lead glass, commonly known as crystal, can look and feel similar to ordinary glass if you don't know what to look for. Many people don't even realize the difference. Lead glass is composed of the same basic ingredients as man-made glass, with an important ingredient added: lead oxide. Glass manufacturers use this chemical in the firing process to improve quality. Lead glass is used for finer glassware and can usually be distinguished from ordinary glass based on physical properties such as cutting and transparency. To correctly determine whether the product is made of lead glass or ordinary glass, you need to follow the steps below.
1. Judging the clarity
Because of the high lead content, the crystals have high optical transparency, usually appearing clear or even white, so called "crystal clear" glass cannot achieve the same level of purity, so glass objects usually have a yellow/green casting or hue.
2. Compare cutting
Adding lead to glass not only improves transparency, but also softens the glass to make it easier to cut. The lead-free glass cut will be rougher and more obvious to the touch, while the crystal cut will have a finer texture and accurate appearance.
3. Compare weight
The addition of lead to a glass object will increase its molecular density, causing the crystal to be significantly heavier than glass. Hold your glass object in one hand and the crystal object in the other hand. The crystal will be heavier and denser than the glass object.
4. Tap the brim
When hit, the crystal will emit a clear bell or "ding" sound. Tap your crystal object lightly and test its sound clarity. The sharper the ring, the higher the lead content. Tap your glass object and you will notice that the glass will only make a dull popping sound. This is because the crystals are more tightly bound due to the lead content and therefore absorb less energy than ordinary glassware.
5. Keep it bright
The simple way to distinguish between glass and lead-containing crystals is to hold each object in front of the light source. Crystals are known for their refracting and inherent ability to bend light. If you hold an object facing the light, it will emit light and project the light into a dazzling pattern. This object is made of leaded crystal instead of ordinary glass.
By following this guide, you will be able to tell if something is made of lead glass or ordinary glass.