Nether Quartz is a crystal-like item from Minecraft Vanilla, which is naturally spawned e.g. in the Nether dimension.
For more information about Nether Quartz, see the official Minecraft Wiki article.
Nether Quartz can be found by sifting the following blocks:
|Soul Sand||100%, 33%|
- ↑ If more than one percentage value is listed, then this item can be obtained multiple times where each number indicates the frequency of obtaining one more.