Centura

Dating to September 1962, Centura Tableware was made until 1977.  From 1970 to 1986 the Centura material also was used to make many styles of closed handle cups, creamers and sugar bowls to co-ordinate with Corelle patterns.  The cups can be either white or Sandstone in colour, and like Suprema, Centura also has a layer of glaze which adds lustre and durability. 

Cups, creamer & sugar bowl made of Centura to match Corelle.

In composition, it is a Barium Aluminosilicate glass-ceramic, and when this mineral occurs naturally it is known as Celsian.  Mechanically Centura is incredibly strong and it is also resistant to heat shock, but its one drawback is that it is not microwave safe.  It is quite likely to be the barium that makes it incompatible for this use, and under microwave energy there is a possibility the metallic content can be released into the food. 

But health concerns aside, Centura absorbs microwaves, becoming very hot while diverting energy away from the food.  The result is a blazing hot dish and lukewarm food, so at the very least, it is an ineffective choice for microwave use.  Centura dishes cannot be used as a substitute for a microwave browning grill.

Centura is completely safe for ordinary tabletop use and it has sufficient heat resistance for baking or warming in a conventional oven.  Although it is a glass-ceramic like Corning Ware, its composition and method of manufacture are geared toward a product resistant to breakage due to impacts.  Its resistance to heat shock is roughly equivalent to that of Pyrex rather than Corning Ware, and Centura is not appropriate for the stovetop or broiler.

Related Articles:

Round-Bottom Cups (1970)
Expressions Cups (1977)
CornerStone Cups (1983)
Centura Tableware Profiles
Which products are safe for the microwave?
What are glass-ceramics?

Source:

"Glass Ceramic Bodies and Method of Making Them", John F. MacDowell, United States Patent 3,201,266