Hey! Sorry for the delayed response, hopefully I can help out though. There are several reasons this might be happening but usually for me this comes up when it is a case of the texture file's name, the mod's mod ID, the texture file’s path, or the block’s name in the code are mismatching with one another.

Unless you’ve named your mod or your block something else entirely you should find these statements are correct (right down to capitalization):

• Your texture is located in your project at: “src\main\resources\assets\examplemod\textures\blocks\amethystOre.png”.
• Your MODID (in ExampleMod.java) is: “examplemod” and the block name is “amethystOre”.

If you’ve got all of that down correctly, it could be something else entirely… Does your language file (en_US.lang) correctly register the block to show up as ‘Amethyst Ore’ in-game?