1. Colourless glass made of almost pure silica
   - quartz glass, quartz, lechatelierite, crystal

Type of: natural glass

• ununhexium
• ununpentium
• ununquadium
• ununtrium
• unusable
• unuseable
• unused
• unusefulness
• unusual
• unusual person
• unusually
• unusualness
• unutterable
• unutterably
• unuttered
• unvaccinated
• unvalued
• unvaned
• unvanquishable
• unvanquished
• unvaried
• unvariedness
• unvarnished
• unvarying
• unveil