See footnotes at end of table, STATISTICAL SUMMARY 31 
 
 
Table 8.~—U.S. exports of principal minerals and products—Continued

1966 
Mineral 
 Quantity Value 
(thousands) 
1967 
— 
 
 
Quantity 
Value 
(thousands) 
Metals—Continued 
Platinum: 
Ore, concentrate, metal and alloys~in ingots, 
bars, sheets, anodes, and other forms, 
 including scrap troy ounces.... 102,031 $13,414 161,585 $19,248 
Palladium, rhodium, iridium, ormiiidium, 
ruthenium, and ormium (metal and alloys 
      includingscrap)         troyounces... 103,425 6,711 118,017 9,723 
    Platinum group manufactures, except jewelry.. NA 3,794 NA 2,378 
 Rare earths: 
    Cerium ore, metal, alloys and lighter flints 
                              pounds.._ 61,620 209 141,338 303 
 Silver: 
    Ore and base bullion_thousand troy ounces.. 369 476 2,365 4 242 
    Bullion, refined                do.. - - - 85,169 110,057 68,404 91,718

 Tantalum: 
    Ore, metal, and other forms 
                        thousand pounds.... 198 1,798 134 1,724 
    Powder                       do.._.... 51 1,564 157 1 839 
 Tin: 
Ingots, pigs, bars, etc: 
 Exports long tons.. - 1,866 6,985 2,050 6,962 
 Reexports do........ 981 3,849 429 1,412 
    Tin scrap and other tin-bearing material 
      except tinplatescrap long tons.... 7,233 1,957 2,957 1,490 
 Titanium: 
    Ore and concentrate short tons_.. 1,300 213 3,027 167 
    Sponge (including iodide titanium and scrap 
  short tons.... 1,733 1,988 1,429 1,703 
    Intermediate mill shapes and mill products, 
      n.e.c short tons.._ 1,371 9,585 1,811 13,344 
    Dioxide and pigments do........ 26,872 7,601 25,852 7,165 
 Tungsten: Ore and concentrates: 
    Exports do...... 98 223 944 2,932 
    Reexports do.. - -- 195 557 269 576 
 Vanadium ore and concentrate, pentoxide, etc. 
  (vanadium content) ........ thousand pounds.. - 1,771 4,226 1,575 4,043

Zinc: 
 Slabs, pigs, or blocks short tons.. - 1,406 749 16,809 4,287 
Sheets, plates, strips, or other forms, n.e.c. 
  short tons 4,921 3,198 3,565 2,709 
       Scrap (zinc content) do...... - 4,469 702 1,665 530 
      Semifabricated forms, n.e.c do...... - ' 3,034 r 1,894 2,161 1,177

   Zirconium: 
      Ore and concentrate do 2,311 326 2,729 360 
      Metals and alloys and other forms..pounds_ 421,516 4,567 637,612 6,909

Nonmetals: 
Abrasives: 
    Dust and powder of precious or semiprecious 
      stones, including diamond dust andpowder 
                        thousand carats  2,403 6,815 4,317 12,526 
    Crushing bort do 58 325 18 210 
    Industrial diamonds do 1,097 4,470 148 924 
    Diamond grinding wheels do 436 3,831 429 2,946 
    Other natural and artificial, metallic abra 
      sives and products  NA 36,812 NA 34,290 
 Asbestos: Urmanufactured: 
    Exports short tons 46,690 5,712 47,356 5,951 
    Reexports do 306 51 362 74 
 Boron: Boric acid, borates, crude and refined 
  short tons 207,359 20,682 186,482 18,710 
 Cement        thousand 376-pound barrels 1,069 4,836 980 4,452 
 Clays: 
    Kaolin or china clay shorttons 253,408. 8,443 321,929 9,921 
    Fire clay do 215,534 3,396 176,367 2,789 
    Other clays do 605,625 19,354 651,366 19,853 
 Fluorspar do 5,732 301 10,345 517 
 Graphite do 3,161 428 3,569 460 
 Gypsum: 
    Crude, crushed or calcines 
                     thousand short tons 38 1,458 39 1,707 
    Manufactures, n.e.c  NA 1,216 NA 1,211 
 Kyanite and allied minerals short tons 17,339 1,131 21,428 1,408 
 Lime do 59,848 1,195 52,143 1,099 
 Mica sheet, waste and scrap and ground..pound& 10,810,194 929 14,301,524
781 
 Manufactured do 537,556 1,612 526,690 1,753