Amber is a type of currency obtainable in Dragons: Rise of Berk through different activities. It primarily comes in two forms: Raw Amber and Polished Amber.
Raw Amber is Amber in its basic form and the most common. It can be obtained from Card Packs, releasing dragons, destroying decorations and statues, Legendary dragon gathering, the Season Pass, and Gauntlets. In this form, Raw Amber cannot be used for much, and will need to be traded for Polished Amber. You can trade in Raw Amber for Polished Amber at Eret's Boat. You can find Eret's Boat southwest of your Meade Hall, near the Treasure Hoard. Eret's Boat can be upgraded to be able to trade for multiple pieces at once.
NOTE: Upgrading Eret's Boat does NOT grant additional Polished Amber for the same amount of Raw Amber. It let's you trade in more pieces simultaneously (ex. 2000 Raw Amber for 2 Polished Amber).
Polished Amber is Amber in its final form and the most rare and valuable. It can only be obtained from Card Packs, the Season Pass, and Eret's Boat. Polished Amber can be used to purchase Statues from the Berk Market. These Statues provide different boosts and perks to enhance your gameplay.