Assertion: opal | /r/HasProperty | impregnated with hardener
Facets:
value: to hide improve
type: PURPOSE
Source sentences:
text: Some opals are also impregnated with colorless oil, wax, resin, plastic, and hardeners to hide crazing or improve durability.
text: Some opals are also impregnated with colorless oil, wax, resin, plastic, and hardeners to hide crazing or improve durability.