Why Is Opal A Mineraloid?
Why Is Opal A Mineraloid? Opal is a mineraloid because it is amorphous hydrated silica. Despite its mineral-like properties, opal’s chemical structure is hydrated with varied water concentration. Because of this variance, the stone’s structure isn’t fixed or organized and thus, qualifies as a mineraloid. Is opal a mineraloid? Opal is a hydrated amorphous form