Minecraft wiki entry for Nether_survival, associated text: Nether gold ore. It drops 2-6 gold nuggets, and attempts to generate 10 times per chunks from levels 10-117 in blobs of size 1-10. It generates 20 times per chunk in basalt deltas, because it can replace only netherrack. Keep in mind that it is still slower to mine in basalt deltas because basalt is slow to mine.
Blackstone. Mining consumes a lot of stone pickaxes, and stone is needed for all tools, furnaces, and brewing stands. It is found in blobs of up to 1-33 from levels 5-28, generating 2 blobs per chunk. You can easily find more than 33 blackstone in one blob if it connects to other blobs
Ancient debris. Ancient debris is essential to obtaining netherite ingots and is found in blobs of 1-3 from levels 8-119. A blob of 1-3 ancient debris attempts to generate once per chunk from levels 8-22, and an additional blob of 1-2 ancient debris attempts to generate once per chunk from levels 8-119. It is difficult to find ancient debris from levels 8-119, and better in low places (levels 8-22). It is the most common at level 15