Adamantite is one of the best ores in the game and arguably better than Mithril for tools, weapons and armor even though it's a lower tier. I'll show you how to get it and the best farming spots. Here's my guide on how to find Adamantite in Hytale.
How to Find Adamantite Ore in Hytale

Adamantite is most commonly found on the Cinder/Volcanic islands which are found in the open sea/water masses. Open your map and look for wide areas of water and go and reveal them as much as possible which is where you'll find these volcanic islands (No need for boats though I recommend a horse). Then, specifically, go into the Cinder Waste sub-biome on these volcanic islands which are the darker red/purple-ish parts. Adamantite Ore will be found around this sub-biome near lava as well as in the naturally generated caves below the island. You'll need an Iron Pickaxe or better to mine it.
Also check out how to find all Ores in Hytale

Adamantite Ingots and Ore can also be found in chests across various areas but this isn't a reliable method of farming it (See below).
How to Farm Adamantite in Hytale
Currently, Adamantite can only be farmed on the Cinder/Volcanic islands in the Cinder Waste sub-biome around lava pockets. Here's mandatory and optional stuff I recommend you bring for farming it:
- You must bring an Iron Pickaxe or higher to effectively mine Adamantite Ore.
- Bring at least a Copper Weapon and I recommend a one-handed one with a shield and a bow as backup for the mobs there (The sword charged move allows you to dash over water if you're not mounted).
- Bring cooked food preferably cooked meat from animals.
- Bring a horse for faster traversal and exploration.
- Establish a teleport for an easier time returning to your base or place a chest near some of the ore pockets so that you can store Adamantite in case you die.
Adamantite is arguably the best ore in the game since it makes more effective gear than Mithril. As soon as you get some ore and smelt it into Adamantite Ingots I recommend first making a Weapon, then Tools/Armor. For the weapons you'll also need Heavy Leather which you can get from Bears (Process at the Tanning Rack) and also Cindercloth Scraps which you can get from mobs around the volcanic island.
That's it for my guide on how to get Adamantite in Hytale and farm it. Check out my Hytale beginner's guide for extra tips.