I like the card concept (generating
![Earth :earth](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/earth18x18.png)
based on the number of burrowed creatures) - an interesting idea with a useful niche in earth-based decks.
As OldTrees notes, however, 3
![Earth :earth](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/earth18x18.png)
is a lot of quanta to generate per turn per burrowed creature. 1
![Earth :earth](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/earth18x18.png)
per turn per burrowed creature might well be more balanced.
Another possibility would be a strip mine (as a spell instead of a permanent) which provides the larger amount of quanta from your original idea (3
![Earth :earth](https://elementscommunity.org/forum/Smileys/solosmileys/../../../images/Misc/earth18x18.png)
per burrowed creature) but only once upon play instead of every turn.
As for the name, diamond seems right for the upped version, but gold seems a bit soft for the unupped version - maybe titanium|diamond as with the earth shield?