What's the plural form of xanthophyllite? Here's the word you're looking for.
Answer
The noun xanthophyllite can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be xanthophyllite.
However, in more specific contexts, the plural form can also be xanthophyllites e.g. in reference to various types of xanthophyllites
or a collection of xanthophyllites.
