Editing Ruby (section)

=== Clarity ===
Because rubies host many inclusions, their clarity is evaluated by the inclusions’ size, number, location, and visibility. Rubies with the highest clarity grades are known as “eye-clean,” because their inclusions are the least visible to the naked human eye.<ref>{{Cite web|title=Ruby and Sapphire Grading Tools|url=https://www.gemsociety.org/article/ruby-sapphire-grading-tools/|access-date=4 May 2021|website=International Gem Society|language=en|archive-date=4 May 2021|archive-url=https://web.archive.org/web/20210504012848/https://www.gemsociety.org/article/ruby-sapphire-grading-tools/|url-status=live}}</ref> Rubies may also have thin, intersecting inclusions called silk. Silk can scatter light, brightening the gem's appearance, and the presence of silk can also show whether a ruby has been previously heat treated, since intense heat will degrade a ruby's silk.