Another alloy containing 40 to 90 per cent. zirconium, the rest being mainly iron, is said to be free from metalloids and oxides, and malleable and ductile. Alloys covered by United States Patent No. 1,151,160 are claimed to be highly resistant to oxidation and chemical reagents. They have a metallic lustre and take a high polish, are readily malleable and ductile, and it is suggested that they may find an important application in filaments for electric lamps, as they are said to have the property of selective radiation. A typical analysis of some of the alloys claimed to have been produced under this patent shows Zr. 0.65 per cent., Fe 26 per cent., Ti 0.12 per cent. and Al 7.7 per cent. A widely circulated statement to the effect that zirconium has been used in Germany in the production of steel for armor plates and armor-piercing projectiles has not been substantiated, so far as the writer knows, by any records of analyses. The use of zirconium for alloying in steel is so new that, pending definite determination by disinterested competent authorities of the exact properties, if any, which zirconium imparts to steel, judgment as to its value for this purpose should be withheld. Zirconium carbide has been patented for filaments for incandescent electric lamps and it has also been used as an abrasive. Tried as a pigment, zirconia has been found to have good covering power and should be considered where protection from acids, alkalies, or gases is particularly desired. The basic acetate has been used for weighting silk, and the pure oxide is used as a substitute for bismuth subnitrate in X-ray work. GEOLOGICAL AND GEOGRAPHICAL DISTRIBUTION Zirconium occurs in nature in commercial quantities as a mixed oxide and silicate known as baddeleyite, sometimes called brazilite, and as the silicate, zircon. Baddeleyite, as supplied to the trade, usually carries 80 to 85 per cent. ZrO₂. The silicate, zircon, carries about 65 per cent. ZrO₂. The oxide deposits, containing as they do a higher percentage of zirconium and the ore being more pure and easier to reduce, will in all probability become the principal source of zirconium. The principal known deposits of zirconium ores are in Brazil, India and the United States, the countries being named in the relative order of their commercial importance. =The Natural Oxide.=--The natural oxide, baddeleyite, or brazilite, occurs only in _Brazil_ in commercial quantities and is described in _Mineral Foote-Notes_ by Meyer,[99] who writes as follows: [99] MEYER, H. C., _Mineral Foote-Notes_, November, 1916, p. 29.