Henry Kissinger reportedly said:
A diamond is a chunk of coal that is made good under pressure.
Perhaps that was the motivation for this which has apparently been going around on Facebook:
It reminded me of I Peter 1:
6 Wherein ye greatly rejoice, though now for a season, if need be, ye are in heaviness through manifold temptations:
7 That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ.
pressure + coal = diamonds
pressure + “lump of coal” Christians = spiritual gold
Are you a “lump of coal” Christian? A weak, dirty, struggling, pathetic “lump of coal” who just isn’t very good at living the Christian life? Trials under pressure strengthen and purify us, changing us, hardening us, making even ugly lumps of coal into precious spiritual gold which will “be found unto praise and honour and glory.”
When God Works,
Pressure Makes Precious
Mind Renewers 
I recently posted this on my husband’s FB wall and commented that this is how we see him. 🙂
Carrying a briefcase and wearing one of those hats, with skinny arms and legs and a funny nose? Poor Patrick.
I always did think he was a diamond in the rough.