Gem Stones
Painting gems always seem to be the thing people don't get around to. Either they painted them in a solid colour, or the paint them with a metallic paint or worse, just leave them unpainted.
Why? They are not at all hard to paint. Simply follow these four steps and it will work just fine.
1: Paint the Gems in a basic colour
2: Add a dark shade to the top, maybe a bit to the left or right side.
I have done it to the left on the images
3: Add some light shade (not white) to the opposite end on the gem
4: Add a dot in the middle of the dark area, voila! A Gem painted.
This technique can be used for may purposes, you can use it for small screens on for example hand scanners, you can use it on a mirrored visor or shades etc.