Leaded Glass vs. Normal Glass

Written by Fiye Ward
on Feb 22, 2010

To ensure our content is always up-to-date with current information, best practices, and professional advice, articles are routinely reviewed by industry experts with years of hands-on experience.

Reviewed by
Charles Ramos, Jr.
on Jun 26, 2023

10-20 hours
•
Intermediate
•
200-5,000

Leaded glass, commonly known as crystal, can look and feel similar to regular glass if you do not know what to look for. Many people don't even realize there is a difference. Leaded glass is made up of the same basic components as manufactured glass, with the addition of one important ingredient: lead oxide. This chemical is used by glassmakers during firing as a quality enhancement. Leaded glass is used for more detailed glassware, and can usually be distinguished from ordinary glass based on physical properties like cut and clarity. To properly determine whether a product is made from leaded glass or regular glass, you will need to follow these steps.

Leaded glass, commonly known as crystal, can look and feel similar to regular glass if you do not know what to look for. Many people don't even realize there is that much of a difference. Leaded glass is made up of the same basic components as manufactured glass, with the addition of one important ingredient: lead oxide. This chemical is used by glassmakers during firing as a quality enhancement. Leaded glass is used for more detailed glassware, and can usually be distinguished from ordinary glass based on physical properties like cut and clarity. To properly determine whether an product is made from leaded crystal or regular glass, you will need to examine these areas in a crystal object and weigh them against that of ordinary glassware.

Tools and Materials Needed:

Glass object (similar size)

Crystal object (similar size)

Step 1--Judge Clarity

Due to a higher lead content, crystal has a high optical clarity, often appearing clear or even white in color, hence the term "Crystal Clear". Glass cannot acheive the same level of purity, therefore the object will often have a yellowish/greenish cast or similar tint instead of pure white.

Step 2--Compare Cuts

The addition of lead to glass not only enhances clarity, it softens the glass--making it easier to cut. Leaded crystal will have a more finished looking, precise cut versus ordinary glass. Unleaded glass is a more brittle product, therefore the cut will be rougher and obvious to the touch. When running your finger over crystal, its cuts have a refined, buttery texture whereas manufactured glass cuts are often sharper and more apparent.

Step 4--Compare Weight

The addition of lead to a glass object will increase it's molecular density and cause two similarly sized objects to have an obvious difference in weight when compared against each other. Hold your glass object in one hand and the crystal object in another, and you will readily feel the crystal to be weightier and more dense than the glass object by comparison.

Step 5--Tap The Brim

When struck, crystal tends to absorb less energy and transmit a clear ringing sound. Tap your crystal object and test its sound clarity. The clearer the ring, the higher the lead content. Tap your glass object and notice the glass only makes a weighted thumping sound. This is because crystal is bonded together more closely due to the lead content and therefore absorbs less energy than ordinary glassware.

Step 6--Hold It To the Light

The simplest way to tell the difference between glass and leaded crystal is to each object up to a light source. Crystal is well known for its spectacular refraction and inherent ability to bend light. If you hold an object up to the light and it sparkles and throws the light into a dazzling pattern, this object is made of leaded crystal, not regular glass.

Step 1 - Judge Clarity

Due to higher lead content, crystal has high optical clarity, often appearing clear or even white, hence the term "crystal clear." Glass cannot achieve the same level of purity, therefore glass objects often have a yellowish/greenish cast or tint instead.

Step 2 - Compare Cuts

The addition of lead to glass not only enhances clarity it also softens the glass, making it easier to cut. Unleaded glass cuts will be rougher and more obvious to the touch, whereas in crystal the cuts have a more refined texture and precise look.

Step 3 - Compare Weight

The addition of lead to a glass object will increase it's molecular density, causing the crystal to be noticeably heavier than glass. Hold your glass object in one hand and the crystal object in another. The crystal will be heavier and denser than the glass object.

Step 4 - Tap the Brim

When struck, the crystal will transmit a clear ringing sound or "ding." Tap the crystal object and test its sound clarity. The clearer the ring, the higher the lead content. Tap a glass object and you will notice the glass only makes a dull thumping sound. This is because the crystal is bonded together more closely due to the lead content and therefore absorbs less energy than ordinary glassware.

Step 5 - Hold in Light

The simplest way to tell the difference between glass and leaded crystal is to hold each object up to a light source. Crystal is well known for its refraction and its inherent ability to bend light. If you hold an object up to the light and it sparkles and throws the light into a dazzling pattern, this object is made of leaded crystal, not regular glass.