material world: clear glass
Friday, September 17, 2010 at 12:00PM 
Transparent or sandblasted, mouth-blown or machine-made, borisilicate or soda…glass. It can take on almost any form imaginable—from purely functional window panes and high performance lab glass to art glass and brilliant crystal chandeliers—the basics don’t do justice to this most versatile material.
Most likely an accidental creation of residue chemicals in an oven, pieces have been discovered in Mesopotamia from 3000BC and Egypt from the late Bronze Age…so much for its delicate nature.
While most transparent glass has a slight green or blue tint—which is caused by iron that acts as a lubricant in the manufacturing process—‘crystal clear’ lead glass is made with lead oxides, instead of calcium, and is usually used for cut stemware or sparkling crystal jewelry. And even though glass has no crystalline structure chemically, the term stuck like qwerty keyboards. 
Early window panes, photo courtesy of: lady_lbrty
Generally speaking, most commercial glass made today is soda glass—a mix of sodium carbonate from soda ash, calcium oxides from limestone, magnesium and aluminum oxides. Heated to temperatures over 2000°F, glass begins as a thick liquid—with a high viscosity—and takes shape as it cools. Shapes can be made by literally mouth-blowing the glass through a long pipe or by machines and molds. Blown glass can be thick or thin and fine, like lumi candleholders, while machine made glass is usually thicker like bari bowls.
As further testament to its durability, glass has been battling the elements of nature as an architectural material for hundreds of years. Stained glass windows brought drama to Medieval stone cathedrals, and early window panes were actually mouth-blown into a flat shape which can be easily identified by their wavy surface and circular centers. In more recent centuries, and in its simplest ‘float glass’ form, they’re the key element of modern structures—from high-rise skyscrapers to International Style homes.
Farnsworth House, photo courtesy of: tinyfroglet
glass, material world in learn
Reader Comments (12)
The table is great but it is too big for my space. Does it come in a smaller size? Can it be made in a smaller size
Hey Rachael!
Unfortunately it only came in one size--sorry!
Too bad the table doesn't come in a larger size - it's a great table at a great price.
I have two small kids and just want to make sure it is tempered glass before purchasing. Can you advise?
Hi Dore!
Funny you should ask since the same question was recently posted on our Facebook page.
The Bolt Dining Table does not have tempered glass. The table top is a clear float glass with dubbed corners (ie. slightly beveled to reduce the sharpness of the edges and risk of chipping) and is 1/2" thick -- glass does not need to be tempered if thicker than 1/4".
We'd love to see the final results so feel free to send pics to facebook.com/cb2.
Good Luck to you!
I actually wondered about the Silverado table, does it have regular glass instead of tempered? I need to cut the glass down and understand tempered glass can't be cut.
Thanks!
Hi Shannon!
Most if not all of our glass tabletops are 1/2" thick and not tempered.
the smart glass top coffee table is tempered...i have 3 small children so it's a concern. just bought--we'll see how it works!
Can the glass be cut down to size? I saw the question before but I'd didn't see the response from Sandra. Thanks
I have the Silverado table and love it! Question: can I purchase the glass top separately and if so, what would be the cost?
Via an independent testing facility, all of our furniture is tested--glass tops with the bases that they were designed to sell with--for stability and strength. So unfortunately we cannot sell only one part of the table.
With that said, I do believe there are resources for glass tops similar to granite for kitchen countertops. Your best bet would be to Google locally since they can be expensive to ship.
Good Luck Anna!
Hi,
Are the Tessa book shelves REALLY strong enough to be bookshelves? I see in the images posted on the CB2 website, it's a mix of a few books and a lot of objects and decor. I really want to use them primarily as bookshelves. Are they really strong enough? Thanks.