Palache- Warren — Chemical Composition of Parisite. 533 



Art. XLV. — The Chemical Com/position and Crystalliza- 

 tion of Parisite and a New Occurrence of it in the Gran- 

 ite-Pegmatites at Quincy, Mass., U. S. A. With Notes, 

 on Microcline, Riebeckite, Aegirite, Ilmenite, Octahedrite, 

 Fluorite and Wulfenite from the same Locality • by 

 Charles Palache and Charles H. Warren. 



Parisite. — The rare fluo-carbonate of calcium and the cerium 

 earths, parisite, was first discovered in 1835 at the emerald 

 mines of Mnso valley, U. S. of Columbia, by J. J. Paris, after 

 whom it was named. It was first described by Bunsen in 

 1845.* Its crystallization was described by Des Cloizeaux,f 

 who also gives the indices of refraction as determined by 

 Senarmont. A paper relating to its crystallization was pub- 

 lished by Vrba in 18864 The mineral was again described 

 by Penfield and Warren, § with chemical analyses, from a new 

 locality in Ravalli Co., Montana, U. S. A., where it occurred 

 in the form of embedded crystals in what appeared to be a 

 decomposed rhyolite. Crystals from Muso valley were also 

 analyzed by them, and the chemical composition was shown to 

 correspond to the formula (R // T) 2 Ca(C0 3 ) 3 . In 1894 A. Nor- 

 denskiold|| described as parisite a mineral from Narsarsuk, 

 Greenland. Later Gr. Flinty re-examined this mineral and 

 showed that it differed from parisite in its rhombohedral crys- 

 tallization, in the relative proportions of its constituents and in 

 its indices of refraction as previously determined. Flink gave 

 it the name synchisite and determined the formula to be 

 (R // 'F) 2 Ca.,(C0 3 ) 4 . It occurred on the surfaces of feldspar or 

 aegirite crystals, or in cavities in alkali granite pegmatite, and 

 with it also occurred the barium-parisite, cordylite, described 

 by Flink and later by Boeggild.** The new occurrence of pari- 

 site at Quincy, Mass., at first thought to be synchisite from a 

 preliminary crystallographic examination and so announced, ff is 

 also in an aegerite-bearing-rock. Murgoci,^ in a paper discuss- 

 ing the origin of riebeckite and riebeckite rocks, notes the pres- 

 ence of rare earth carbonates (parisite?) with the riebeckite 

 and aegirite. Tacconi also notes the presence of parisite in 



* Bunsen, Lieb. Ann., liii, 147, 1845. 

 fMin., ii, 162, 1874. 



\ Ber. Bcehm. Ges., 647, 1886, and Zs. Kr., xv, 210, 1888. 

 § This Journal, viii, 21, 1899, and Zs. Kr., xxxii, 1, 1899. 

 || G. For. Fork., xvi, 338, 1894. 



■[[Bull. G. Inst. Upsala, v, 81, 1901 ; see also Boeggild, Medd. om. Green- 

 land, xxiv, 29, 1901. 

 **Medd. om Groenland, xiv, 236, 1898 ; xxiv, 42, 1901; xxxiii. 101, 1906. 

 tf This Journal, xxviii, 450, 1909. %\ This Journal, xxx, 137, 1905. 



Am. Jour. Sci.— Fourth Series, Vol. XXXI, No. 186.— June, 1911. 

 36 



