Here are all the ways to get Amethyst:
- cut down white or black marble, snowy peaks, lava rocks, underground crystals, underground rocks, ruins, and scrap metal;
- make it in Gatehouse;
- win it in the Flag of Hope (Flying Island);
- get it from Morgan’s Chests in Caravel sails (Tortuga);
- get it on day 18 of the daily gift;
- find it in the Admiral's Set in Henry's Shop (Tortuga).