This texture pack outlines ores to make them easier to see in the dark. It outlines all overworld ores, and nether ores. The outline of the ores even allows them to be seen when the are submerged in lava, because lava is not a full block. (See gallery)
NOTE: There is not a specific file for 1.13, because of the texture update. However, you can use the 1.12 download for 1.13 as well. Minecraft will say that it is not compatible with the current version, but you can still enable it, and it will work like intended.
This will also work on any snapshot in between versions, but Minecraft will give an error message. You can ignore it most of the time, but for snapshots around 1.13 and 1.14, as well as 1.16 and 1.17, be careful to pick the right one, because of the texture update, otherwise your game might look pretty weird.
If you want a blue ancient debris version, you can download it here (https://modrinth.com/resourcepack/simple-outlined-ores-blue-netherite-edition)