“ The powdery metal burns readily in air, the crystalline metal requires to be heated in an oxyhydrogen flame before it catches fire. Mineral acids generally attack the crystallized metal very little even in the heat; aqua regia, however, dissolves it readily, and so does hydrofluoric acid. In its chemical affinities zirconium resembles titanium, cerium and thorium; it occurs in company with these elements, and is tetravalent in its more important salts.
Zirconium oxide or zirconia, ZrO2, has become important since its application to the manufacture of mantles for incandescent gas-lighting. ”

“ When the mass is quietly fusing, the crucible is heated for two hours in a wind-furnace. The porcelain-like melt is powdered, boiled with water, and acidified with hydrofluoric acid, and the residual potassium fluosilicate is filtered off. ”

“ The hydroxide readily loses its water at a dull red heat and passes into an hydride with vivid incandescence. Zirconia can be obtained crystalline, in a form isomorphous with cassiterite and rutile, by fusing the amorphous modification with borax, and dissolving out with sulphuric acid. The anhydrous oxide is with difficulty soluble even in hydrofluoric acid ”