Here is a Quacrown, it has a pink-quartz color, but also a red crystal color that I mixed. A Quacrown like this does have to have quartz to make it a Quacrown, but it can also have kinds of minerals as a part of its body.
They just need two main things to be a Quacrown:
1 is quartz, and 2 is at least one horn (and maybe something else if that works too)