What’s the difference between glass and crystal?

 

All crystal is glass, but not all glass is crystal. How does that work? What is the difference between glass and crystal?

Well, your trusty glass artists is here again to explain the differences and similarities between these two versatile materials.

The term crystal is often used to refer to glassware that has a more fine and elegant form.

However, that is not the official difference between these two materials.

So, what type of glass is crystal? Can it be recycled? And how are they different?

Glass

Glass is an inert and natural material, made from raw materials that are abundant in nature and sustainably sourced, such as sand, soda ash and limestone.  Other minerals like silica and barium can be added to manipulate the color, durability, and thickness to create different types of glass – such as that we know as crystal.

• Glass is typically more affordable than crystal
• Is non-porous and dishwasher safe
• Borosilicate glass provides a high-end durable glass option

Crystal

Unlike the name suggests, crystal glass doesn’t contain a crystalline structure. The name stems from the Italian word “Cristallo”, which was used for high-end hand-blown glass in Murano, Italy. 

Different countries and practices differ on the minimum lead content that earns a “crystal” classification.  2% by weight in USA and up to and up to 18-35% in Europe! 

Sometimes it goes even higher if it isn’t for use as a practical vessel, like a statue or something. 

So this means crystal is a subcategory of glass, made in the same way, but with different components.

That’s the reason why all crystal is glass, but not all glass is crystal.  For a while, people called crystal “Lead glass” but the name didn’t ever come into common usage.

According to John Kennedy, Head of Technical Services at the wonderful Waterford glass company in Waterford, Ireland, there are very specific guidelines for what constitutes real crystal.

There are three primary criteria for crystal as established by the European Union in 1969: a lead content in excess of 24%, a density in excess of 2.90 and a reflective index of 1.545. However, outside of the European Union, this definition is usually disregarded. In the United States, any glass with more than 1% of lead content is termed as crystal.

It contains strengthening minerals like lead-oxide, potassium carbonate or barium oxide to make the material more durable. The added strength allows the crystal to be molded into thin, delicate shapes, which we often associate with sophisticated craftmanship and elegance. 

In the end it’s a personal choice as to whether you want to take the risk of using leaded crystal to serve or eat or drink with. If, in the end, you simply cannot comfortably drink a glass of wine from your leaded crystal then consider using some of your pieces as display items or as upscale vases for flowers. There’s certainly no other material that glitters and shines like crystal- one of the many reasons why these pieces are considered heritage pieces in many families.  More details from “Dusty Old Thing“.

Glass vs. crystal: which one can I recycle?

Glass itself is sustainable, inert, and 100% recyclable, reusable and refillable. It can be recycled endlessly without losing any of its quality or purity. 

Recycled glass, also called cullet, is actually the most important ingredient in glass manufacturing.  The benefit of using cullet to produce new jars and bottles is that it uses 40% less energy than virgin materials to be melted and shaped. By increasing the amount of cullet that goes into production of new glass products then precious natural resources and energy are being conserved!  Every 10% increase in cullet, leads to a 3% reduction in energy consumption. That’s why it‘s so important for all of us to recycle our glass containers.  

Crystal on the other hand is one of the types of glass that cannot be recycled because it is made with added materials, such as barium, potassium and zinc oxide.  That’s why it can’t be recycled with your jars and bottles.

Glass vs. crystal: which one is strongest?

Strength and durability

Because crystal is made with added minerals, the material is stronger and more durable.  Of course, crystal should be handled with care, but your collection of crystal glass ware should never lose its shiny appearance and hopefully it’ll hardly ever scratch. 

Unlike glass, crystal is soft enough that with special tools it can be hand-cut with details added to its surface without compromising its durability or structure. The material can also be molded and shaped more easily than glass, allowing the artist to add different intricate patterns.  However, part of the reason crystal is more expensive than glass, is also because it is perceived as more elegant and sophisticated. Its added ingredients make it slightly porous, giving it the ability to refract light.  Crystal should never be put in a dishwasher or washed with hot water or harsh chemicals.  (Its slightly porous – remember.)

Glass is a cheaper option and widely available because it requires less materials to be produced, making it more affordable for us all. It can also be crafted into a wide range of different designs.

What are glass and crystal best used for?

Glass is one of the most stable packaging materials. Thanks to its inertness, there is no risk of harmful chemicals coming into contact with food or drinks. This makes it a safe option for long-term storage and protection of food and beverages.  

Crystal, in comparison, contains additional elements, namely lead oxide. Due to the possible contamination from lead oxide into your food or beverages, it’s often advised not to use this for food storage. However, under normal consumption conditions, little hazardous lead is released, making it safe to use.  

That said, the increasing concerns of lead crystal have led to the development of “lead-free crystal glass.”  To make crystal safer for food storage, the only difference is that the lead oxide in the production is replaced with barium oxide, zinc oxide, or potassium oxide.

 

How can you tell the difference between glass and crystal?

The main difference is that crystal contains anywhere from 2–30% minerals (lead or lead-free), making it possible to produce durable but thin glasses.  

It is also more transparent, brighter and thinner, making it a desirable choice for high-end glassware and decorations. Its refracting properties are like a prism, decomposing the light coming through in the form of a rainbow. 

Regular glass is often a little bit foggy in appearance and can typically feature a tint based on the ingredients in its composition. It can have a green tint if made with iron or a blue tint if made with soda lime. It’s also typically lighter in weight in comparison to crystal pieces of the same design.  

Lastly, the most famous difference is the sound. Glass provides a dull, short, and subtle chime when tapped or flicked with your finger. When tapping crystal you hear a satisfying bell-like ringing sound, as different added materials allow the sounds to be slightly prolonged. 

So, now that you know all the differences between glass and crystal and how to spot them, you can make more informed decisions when choosing the right products to buy! 

What glass do I use in my studio?

I don’t use crystal glass in my studio I use glass that’s called Soda Glass that we call “float” glass because of how its made.  It “floats” through the manufacturing process on rollers. You can see the slight green tinge here in a the glass items I’ve made using float glass, like this lovely 50 x 50 Christmas “Sunflower” platter and attendant sushi plates. Float glass is much cheaper than the coloured art glass I use and often looks really great. If you want to make something in float glass, please let me know by emailing me at [email protected] and I’ll create a workshop especially for you.

 

 

Here are a few more functional works that I have created using “float” glass. It’s such a flexible product and unlike crystal it is dishwasher safe.

 

 

Thank you, as always, for reading!

talk soon,

jenie

Tags: Bacarrat crystal decanters float glass glass v crystal Lalique lead crystal lead glass lead levels Orrefors Waterford Ireland