You can find out the rarity by looking at the bottom left symbols: common (circle), uncommon (diamond), rare (star) there are also holofoil/shiny versions called holo rare and reverse holo rare
Deconstructing a Magic: The Gathering Card There are eight major parts of a Magic: The Gathering card that allow players to understand how it is played, how rare the card is, and more
Once youve hit six Ink in your Inkwell, Ruby/Amethyst starts to get scary strong
He draws a card for each Aura and Equipment he's wearing so the card advantage can be quite explosive
Still, if you don't already have the rare duals, replacing them with Contaminated Aquifer and Dismal Backwater is a fine plan for the short term, although in the long term, you'll probably need to upgrade to compete at the higher ranks