How to Decide Between
Crystal and Glass
“What’s the difference between crystal and glass?” At Custom Craft we hear this question a lot.
Customers are sometimes surprised to learn that crystal is actually a subcategory of glass. In other words, all crystal is glass, but not all glass is crystal.
What Is Optical Crystal?
Optical crystal (sometimes called “hard crystal”) is made by replacing lead oxide with barium oxide, zinc oxide, or potassium oxide. The resulting hardness and high clarity makes optical crystal ideal for camera and telescope lenses (hence, the name).
Red Optical Crystal Award
In 1996 optical crystal was first introduced to the award industry, but it was prohibitively costly. Today, a less-expensive version is used, known as K9.
Because optical crystal is lead-free, it’s harder than leaded glass but offers the same clarity. Strictly speaking, however, lead crystal is the only “true” crystal; non-lead crystal is a brilliant form of glass.
There are basically four characteristics that differentiate crystal vs. glass: composition, color, strength and refractive index. Both glass and crystal offer unique qualities for your award design.
Composition
Silicone oxide (i.e., sand) is the basic ingredient in both glass and crystal. The most popular glass used today is soda-lime glass, which combines the silica with lime and soda.
This mixture is fired under intense heat and then blown or molded into its final shape. Glass awards will often contain small bubbles or chill marks. These “flaws” can actually enhance the award’s appearance, giving it a distinctive character.
Crystal is composed of silica, lead oxide, potash or soda, and sometimes a few other additives. The primary component which differentiates crystal from glass is the lead, which results in the crystal’s clarity and beautiful sparkle.
In the U.S., any glass with more than 1 percent lead oxide content is considered crystal. True lead crystal (sometimes known as “soft crystal”), on the other hand, must contain at least 24 percent lead oxide.
Color
Crystal is always completely clear unless color is added (hence, the expression “crystal clear).
Jade Glass Award
In contrast, glass typically contains a hue of some sort, however slight. For instance, a green color (“jade glass”) is produced when the silica used contains a certain amount of iron ore.
Glass with a slightly blue tint is made from silica containing less iron ore, while glass made with soda-lime has an aqua tinge. Other tints for glass include gray, bronze and black.
Strength
Glass is very strong–especially jade glass—which is one reason it’s commonly used in the production of recognition awards.
Crystal is thinner and more fragile than glass. (There’s a reason it’s often reserved for special occasions.) The lead in the crystal makes it soft and malleable, allowing the creation of more detailed patterns and designs.
Refractive Index
A material’s ability to refract light—its refractive index–is one way of measuring its clarity.
Giphy.com Image
Crystal has a higher refractive index than glass (above 1.5). The higher index increases the degree to which the material separates light into its colors.
This is why crystals are able create color prisms by dispersing light in a rainbow of hues when held in a certain position.
Glass generally has a refractive index of 1.46 or lower.
Which Is Better for Your Award?
The awards you present speak for your organization long after the ceremony is over. Crystal and glass each offer distinctive characteristics and can provide a meaningful symbol of recognition.
Crystal vs. glass… Which is better for your award? Let the experts at Custom Craft help you decide which will work best for your special event. Call us today!
Sources:
Featured Image: Pixabay
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