This effect resembles luster, and is caused by light reflection from inclusions or texture inside the gem. Luster is light reflected from the surface of the gem and sheen is reflection from inside the gemstone.
shininess: the visual property of something that shines with reflected light
splendor; radiance; shininess; To shine; to glisten; beautiful, good-looking, attractive; radiant; shiny
A soft luster on a surface
Keep under careful or protective observation
a small portable timepiece
look attentively; "watch a basketball game"
Look at or observe attentively, typically over a period of time
Secretly follow or spy on
a period of time (4 or 2 hours) during which some of a ship's crew are on duty
Casio Sheen
another chrono! weeeee!!! My new favorite watch from my bee...=) took me quite a while to take a picture of it though, been really busy busy busy. =)
Sheen on Queen
Charlie Sheen's BiPolar Awareness Walk; Toronto's Mounted Police Unit, Queen Street Toronto 2011