Chemical composition of the Coffinite from the Woodrow Mine, New Mexico, U. S. A.

코핀석(石)(Coffinite)의 화학조성(化學組成)에 관(關)한 연구(硏究) -미국(美國) 뉴멕시코주(州) 우드로광산산(鑛山産) 코핀석(石)을 중심(中心)으로-

Chemical analyses by electron microprobe indicate that the well-crystallized botryoidal coffinite with radial fibrous structure from the Woodrow Mine, New Mexico, U.S.A. has the formula ($U_{0.85}Ca_{0.14}$) $(Si_{0.86}P_{0.11}Al_{0.06}V_{0.02})O_2(OH)_4$, or ideally (U, Ca) (Si, P)$O_2(OH)_4$. It can be more simply designated as ideal formula $USiO_2(OH)_4$. This new formula is proposed for the coffinite.