Calciform Pools is a uncommon Land card from Time Spiral (TSP), collector number 270. Current market price: $0.29 (foil $1.22), TCGplayer market prices via Scryfall.
{T}: Add {C}. {1}, {T}: Put a storage counter on this land. {1}, Remove X storage counters from this land: Add X mana in any combination of {W} and/or {U}.