The Differences Between Glass and Crystal Glassware

Lead content

• The main difference between crystal and glass is the lead content. An addition of 24 percent lead oxide added to glass is required for classification as true crystal glass. However, other levels of lead additives are considered crystal in different parts of the world. In the United States, additive levels as low as 1 percent are considered crystal. Typically, around the world the lead levels in the glass must be between 3 and 15 percent to qualify as crystal. In Europe, the classification for crystal is set between 10 and 30 percent lead. It is important to note that high additives in lead can be dangerous. If hot liquid is poured into crystal with a high lead content, the lead can leach into the liquid.

Fragility

• The addition of lead into glass reduces the "give" in the glass. Lead added to glass causes the glass to become extremely brittle. Because of this, crystal glass is more fragile than regular glass. This is why crystal is often more expensive than regular glass.

Refraction

• Lead added to glass increases the refraction rate, which is how light bounces off of glass. This is because lead is a dark, solid metal and light reflects off it. Regular glass absorbs light, allowing it to pass straight through. Therefore, crystal is more sparkly than glass, even when cut in the exact same way.

Cutting

• Crystal is often cut differently than glass. One of the reasons for this is that glass is a fairly soft material. The addition of lead makes the glass harder and easier to cut. Crystal can be cut with sharper edges and in more places without weakening the integrity of the piece. Also, more cuts in crystal leads to more light refraction. Glass usually has to be cut with soft edges.