Needless to say,
nothing beats the turquoise-blue perfect gem that is the diamond in Minecraft
but for those who want to try a different look
I humbly offer you my resource-pack
Diamonder Diamond
Aiming to make the diamond smaller, rougher, less turquoise and more crystalline
Overhauling diamond items, blocks and models for a more accurate diamond look
For all changes see images tab
P.S.
For Optifine users
There are some rename items based on my initial attempts at pixel art:
Any Ideas and feedback are much appreciated.
Enjoy!