I actually kinda liked the shovel... if the rest didn't tie it...

I actually kinda liked the shovel... if the rest didn't tie it too strongly to just gold or the Australian continent I'd have said it's a winner.

Regarding the original, I'm still not convinced by the tin/silver... right next to the gold and ruby it looks... weak.

Maybe doing a regular five sided shape in black could look a little like coal? Call it aspirational,... but it would then cover a nice range of resources to go with the company name. Gold, gemstones, coal... only worry is that the black of the coal will blend too much with the text, but I couldn't say for sure without seeing it.