| Loss of alkalies in volcanic glass by post-depositional alteration and devitrification has been well documented. |
| High-viscosity silica gel produced by the hydration and devitrification of volcanic ashes can eventually concentrate in any open space, such as the cast of a limb. |
| The presence of glass 4 billion years old on the Moon indicates that water is crucial to the rate of devitrification. |
| All melt inclusions and matrix glasses chosen were completely glassy, i.e. they had not undergone any devitrification and did not contain microlites or microphenocrysts. |
| We, also, attempted to illustrate the relationship between devitrification of the rigid amorphous fraction and crystallization kinetics. |
| These structures may be evidence of early nucleation and devitrification that preceded that in the surrounding host rhyolite. |
