A @[email protected] in which a supercooled melt yields, on cooling, a glassy structure. Below the @[email protected] the physical properties vary in a manner similar to those of the crystalline phase. Example: Lithium disilicate crystals melt at \(1305\ \text{K}\); the melt can be supercooled to the @[email protected] at approximately \(773\ \text{K}\) below which the viscous liquid freezes to a rigid amorphous glass.
PAC, 1994, 66, 577. (Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)) on page 583 [Terms] [Paper]