Is 100% grit okay for a lithops that will be living in a plant cabinet?

The humidity in the cabinet is usually 60-80%, depending on how recently i've watered the other plants.

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Also, are there any other inorganic amendments I should add as well? I have the granite chicken grit (no additives, 100% rocks), pool filter sand, and perlite on hand, but I dont mind grabbing other stuff