Knives Without Practicality

Knives Without Practicality

If you found this curiosity in the kitchen area at a Queen B sale, you might think you’d come across something from an old fairytale; a 9″ knife made of pressed, sharpened glass. And it is from the past, just not the ancient past; it was made in the late 1930s or 40s.

The Cryst-o-lite knife hardly seems practical, but there were competing brands such as the New Vitex Glas Knife that made it into the 1939 New York World’s Fair. Pre-internet and pre-Amazon, World’s Fairs were a combo of trade show, amusement park and the United Nations, where countries and companies competed to show off their best stuff, such as fancy, futuristic ‘crystal’ knives.

The Vitex Glas Knife was presented in a box sporting the fair’s logo, with the slogan “Always Sharp, Sanitary, Stainless”, much like this knife’s box copy “Always clean, always sharp, perfect for slicing.” The emphasis on the glass knife’s clean qualities is due to metal blades at the time being made of carbon steel, which the acid in many foods will badly stain. The process of developing stainless steel had begun 100 years prior but in the 30s and 40s many households still used knives that could stain and rust. The eternally clean glass knife had modern appeal.

Produced by companies that made pressed glass table wares, glass knives come in the many of same colors as other Depression Glass: clear, pink, purple, and more rarely, uranium green or ice blue. Their handles can be plain or decorated with starbursts, diamonds, or flowers like this one. Like any pressed glass, these knives are breakable. According to the manufacturers they should only be used with a wooden cutting board, and please stick to cutting citrus fruits, tomatoes, meringue pies, cakes, and molded Jellos; no T-bone steaks!

And in case you’re wondering, yes – in spite of their fragility, glass blades can draw blood!

Which shouldn’t be a surprise considering that flaked glass blades have been used for hundreds of thousands of years. These obsidian arrowheads from another QBO sale are from the ancient past – examples of the earliest cutting edge known to humans. Long before we could smelt metals, humans gathered naturally occurring obsidian glass from the slopes of volcanos and worked it into tools. Obsidian blades have been tested and proven sharper than modern scalpels, as they would have to be to slice through mammoth hide. Scandinavian fairytales tell of a Mountain of Glass, and the Game of Thrones saga featured sword blades made of ‘Dragon Glass’ – fantastical references to the place volcanic glass holds in human history.

The newest glass blades were invented in Japan in 1997. Made of zirconium oxide, they are marketed as ‘ceramic knives’ and can be black, or white like this one from a Beehive sale. Blades are produced by sintering; dry- pressing powdered zirconia and alumina into a mold at 300 tons of pressure and firing at a scorching 2000 degrees centigrade. They are then sharpened with ground diamond dust. Ceramic knives are touted as noncorrosive and exceptionally hard so they stay sharp longer than steel. But they can also shatter if handled roughly and can only be used on soft foods, same as the old-timey glass knives. They are not popular with professional chefs but have many fans among home cooks.

It takes an expert to restore an obsidian or ceramic blade, but depression glass knives can be sharpened at home with the same diamond files used on lapidary stones or fish hooks. This file is from the garage at (where else?) a QBO estate sale. See you soon.