Franklinite and zincite are not fluorescent. The ore mostly consisted of franklinite and willemite and several other minor minerals. It is found in association with calcite, franklinite, willemite, hardystonite and clinohedrite. The mineral association (assemblage) from Franklin includes willemite, zincite and franklinite. Other minerals often associated with hardystonite are franklinite, diopside, andradite garnet, and esperite (fluoresces yellow). Franklinite is a mineral first described at Sterling Hill Mine. Franklinite was a minor ore of uranium, sulfuric acid, and mercury.