Frit is a mixture of inorganic chemical substances produced by rapidly quenching a molten, complex combination of materials, confining the chemical substances thus manufactured as nonmigratory components of glassy solid flakes or granules. This category includes all of the chemical substances specified below when they are intentionally manufactured in the production of frit. The primary members of this category are oxides of some or all of the elements listed below. Fluorides of these elements may also be included in combination with these primary substances.: Aluminum; Antimony; Arsenic; Barium; Bismuth; Boron; Cadmium; Calcium; Cerium; Chromium; Cobalt; Copper; Gold; Iron; Lanthanum; Lead; Lithium; Magnesium; Manganese; Molybdenum; Neodymium; Nickel; Niobium; Phosphorus; Potassium; Silicon; Silver; Sodium; Strontium; Tin; Titanium; Tungsten; Vanadium; Zinc; Zirconium