Cheapest priced copy (Stronghold): $1699.99 at Card Kingdom, near mint, their price list as of .
Mox Diamond 
Artifact · Rare · Stronghold · #138
If this artifact would enter, you may discard a land card instead. If you do, put this artifact onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $1699.99 to $2299.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Stronghold | 138 | Rare | $1699.99 | — |
| From the Vault: Relics | 10 | Mythic | — | $2299.99 |
One ruling from Wizards of the Coast
- 1 May 2008If you don't discard a land card, Mox Diamond never enters. It won't trigger abilities that look for something entering, and you won't get the opportunity to tap it for mana.