That's a weird combination of a white condition and a green condition.

You're right.

This came about as I pondered artifact mana acceleration and how it's not allowed to happen below 3 CMC anymore outside of green.

I think the exact abilities on this need to be tweaked to something appropriate (not sure what, even the lifegain may be too strong given Ajani's Mantra), but I really like the concept of a mossy rock, and the "sometimes produce mana" idea for a cheaper lesser mana rock.

For more, Pristine Talisman gets to unconditionally produce life and mana, so this seemed fair to me.

I really wish they'd just print an artifact that costs and taps for , just so we have a standard to work with. Maybe even enters the battlefield tapped, or some other minor drawback. Seems the problem with the mana rocks wasn't that they were too cheap, but that they were too plentiful. Sticking to "there's only one that's reasonable to print at " would solve much of that.

­Sol Ring got a recent reprint? That's like the opposite of what you wanted ;)

Sol Ring wasn't reprinted in a normal expansion. It's been reprinted in every Commander deck, because it's deemed fair for Commander but not normal expansions.

Jmgariepy: You mean something like Guardian Idol? Or Sphere of the Suns?
I got the idea that the exact problem with mana rocks was that their cheapness infringed on Green's slice of the pie. The other colors no longer get access to ramp below , hence the Boros Keyrune cycle, and the Abzan Banner cycle, and Vessel of the Endless and friends.