Do You Have a Pyroceram Dish in Your Cupboard?

August 21, 2022 $7,000.oo Vintage Corning Ware Blue Cornflower 2-Quart Casserole Dish A-2-B without Lid

September 8, 2022 $6,000 Corning Ware Cornflower Blue Rare 1958 Original Vintage Pyroceram CorningWare | eBay

An estate sale picture illustrates the stability and popularity of CorningWare® . These pieces are over 50 years old! 

CORNINGWARE® facts:

• Cornflower blue - petite blue posies on a solid white background - was the first pattern, it was produced for 30 years
• The first trade stamp for the CORNINGWARE® was embossed on the bottom as "CORNING Pyroceram T.M. Made in U.S.A." and the style code. These 1957 pieces, with the distinctive mark are highly valuable and sought by collectors.
• The first pieces with the simplistic embossed bottom stamp were made in 1958-1959. 
• The signature stylized flame (looks like an enhanced asterisk) was added to the embossed signature in 1959, on the bottom of the 7" skillet, 9" skillet, and a 2 1/2-quart saucepan.
• By 1960-1961 a "Blurry Blue" ink stamp was used rather than embossed bottom signature.
• The "Pyroceram" reference was absent by 1961. The addition of "Made in U.S.A. and the return of style/model is visible on cooking dish bottom, in black ink now, thru 1966.
• The "Cornflower" signature was added by 1966. 

It is these pieces, produced in the first decade of CORNINGWARE® which are most coveted. Additional details of the signature bottoms are available at the Corningware411 blog. 

The two inventors attributed to the Pyroceram designs are  

• James W. Giffen | Legendary Scientists | Corning  and James William Giffen (1903-1997) - Find a Grave Memorial
• Dr. S. Donald Stookey | Legendary Scientists | Corning and S. Donald Stookey, chemist who created kitchen staple CorningWare, dies at 99 - The Washington Post

Where else is Pyroceram used?

• Classified by NASA as a "glass-ceramic" product  
• Mirrors in astronomical telescopes.
• Transparent variation was used by Corning France for their Visions cookware in the late 1970's
• National Institute of Standards and Technology ( NIST ) certified Pyroceram9606 as a material for thermal conductivity measurements.

What is the difference between PYROCERAM (CorningWare) & PYREX?

• CORNINGWARE® is generally more expensive than Pyrex
• Older Pyrex dishes were made of glass with borosilicate but now it is tempered soda-lime glass.
• Borosilicate glass is more durable than the tempered soda-lime glass
• Pyrex is more susceptible to chips & cracks
• Pyrex cannot be used on a stovetop or under a broiler
• Older CORNINGWARE® can go from refrigerator/freezer to oven
• How valuable are the pre-1960 pieces?  This year on ebay these prices were realized:

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