Terra Crystal

There are 7 different Terra Crystals, from which, tools like swords and picaxes as well as armour can be made. The types of crystals are plains, jungle, desert, ocean, mountains, dark oak forest and mooshroom. There are 50 of each type in the crystal dungeons for their respective biome; one of each dungeon will generate every 15,000 blocks, making these gems incredibly rare in survival mode. You can make blocks out of the gems as well, but most notably, by surrounding a beacon with 8 of one type of gem, you get a biome specific beacon. This beacon still works in other biomes to a lesser effect, but if you had a plains beacon powered in a plains biome, the effects you choose would be VERY effective. The tools would also be extra effective as well. Now, the means of getting these crystals... each dungeon has a biome specific boss. By beating that boss, you obtain a "plains bedrock key" or "desert bedrock key" depending on the biome once again. These bosses would be, in all fairness, INCREDIBLY DIFFICULT. But the bedrock keys, they unlock a biome's bedrock door. Any blocks touching a bedrock door that don't naturally generate become unmineable, but fear not, that key unlocks the door and the dungeon can be removed as you see fit. As to combat trolling, the door should be inaccessable through the creative menu, the /give commamd, and only accessable through genuinely painstaking hacking. Which is something few have the gumption to sit down for days on end and do.