| 501 / | HD | COMPOSITIONS: CERAMIC |
|
| 1 | DF | CERAMIC COMPOSITIONS {15} |
| 11 | DF | .~ Glass compositions, compositions containing glass other than those wherein glass is a bonding agent, or glass batch forming compositions {11} |
| 53 | DF | .~.~ Silica containing {3} |
| 55 |  | .~.~.~ 40 percent - 90 percent by weight silica {7} |
| 56 | DF | .~.~.~.~> And halogen or nitrogen {1} |
| 60 | DF | .~.~.~.~> And lead {2} |
| 63 | DF | .~.~.~.~> And phosphorus, niobium, or tantalum |
| 64 | DF | .~.~.~.~> And yttrium or rare earth (i.e., elements with atomic numbers 39 or 57-71) |
| 65 | DF | .~.~.~.~> And boron {1} |
| 68 | DF | .~.~.~.~> And aluminum or iron compound {1} |
| 72 | DF | .~.~.~.~> And divalent metal oxide (e.g., oxides of zinc, cadmium, beryllium, alkaline earth metal, magnesium, etc.) |