AskDefine | Define vitreous

Dictionary Definition

vitreous adj
1 of or relating to or constituting the vitreous humor of the eye; "the vitreous chamber"
2 relating to or resembling or derived from or containing glass; "vitreous rocks"; "vitreous silica"
3 (of ceramics) having the surface made shiny and nonporous by fusing a vitreous solution to it; "glazed pottery"; "glassy porcelain"; "hard vitreous china used for plumbing fixtures" [syn: glassy, vitrified]

User Contributed Dictionary

English

Etymology

From vitreus 'glassy, transparent'.

Adjective

  1. Of, or resembling glass; glassy
  2. Of, or relating to the vitreous humor of the eye
  3. In the context of "of ceramics": having a shiny nonporous surface
  4. Of a semi-crystalline substance where the atoms exhibit short-range order, but without the long-range order of a crystal

Derived terms

Noun

  1. In the context of "by elision": The vitreous humor.

Extensive Definition

Vitreous refers to a material in an amorphous, glassy state (in contrast to a crystalline state). In such a state, the constituent atoms do not exhibit the long-range order that is characteristic of crystals. However, they still exhibit short-range order -- the separation of atoms and/or the lengths of covalent bonds are very close to their typical equilibrium distances. The creation of a vitreous material by supercooling or by addition of additives prior to cooling is called vitrification.
Under certain conditions, vitreous materials may begin to rearrange themselves into crystals. This process is referred to as devitrification. Natural volcanic glass, obsidian, will de-vitrify or crystallize over extended periods of geologic time. Devitrification can also occur in glass items that are regularly washed in dishwashers due to the chemicals involved in their detergents.

Other uses

  • When applied to whiteware ceramics, vitreous means the material has an extremely low permeability to liquids, often but not always water, when determined by a specified test regime. The microstructure of whiteware ceramics frequently contain both amorphous and crystalline phases.
  • A vitreous luster in mineralogy refers to a glassy luster or sheen of a mineral surface. The minerals quartz and fluorite exhibit a vitreous luster.
  • The vitreous humour (British spelling) or vitreous humor (U.S. spelling) is the clear gel that fills the space between the lens and the retina of the eyeball of humans and other vertebrates.

References

vitreous in Spanish: Vítreo
vitreous in Portuguese: Vítreo
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