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