From Gilbert + -ite, after Davies Gilbert, British philosopher. <span class="searchmatch">gilbertite</span> (uncountable) (mineralogy) A particular kind of muscovite. 1836, Thomas Thomson...
Genesis of Deposits[1], page 108: […] contemporaneous with gold are <span class="searchmatch">gilbertite</span>, leptochlorite, tourmaline, iron sulphides, feldspar, (rare) carbonates...
Genesis of Deposits[2], page 108: […] contemporaneous with gold are <span class="searchmatch">gilbertite</span>, leptochlorite, tourmaline, iron sulphides, feldspar, (rare) carbonates...