MINERALOGY. 671 



Bradbury, made at the laboratory of Prof. J. W. Mallet, seems to show 

 that the composition of this topaz is unusual in having three-fourths 

 of the oxygen replaced by fluorine, instead of one-half, as usual. Asso- 

 ciated with the topaz are a number of minerals, the most interesting 

 being triplite, triphylite, columbite, and beryl. Stoueham also afforded 

 some very hue aquamarines. One crystal that was found loose in the 

 soil had a length of 5 inches, and was perfectly transparent and of a 

 rich sea-green color. Auburn, Me., has recently afforded some beauti- 

 ful tourmalines, mostly of smaller size, though one had a length of 4 

 inches; they have delicate shades of pink, blue, and green. A paper 

 on this locality was also read by Mr. Kunz at the Minneapolis meeting 

 of the Association, as were others describing the occurrence of large 

 crystals of andalusite at Gorham, Me., and of transparent white garnets 

 near Hull, township of Wakefield, in Canada. 



Mr. W. E. Hidden (Amer.Jour. Sci., xxv, 393) describes the occurrence 

 of some remarkable fluid-bearing quartz crystals in Alexander County, 

 North Carolina. From a single large pocket 400 pounds of fine quartz 

 crystals were obtained, and many fragments. Some of the crystals con- 

 tained enormous cavities (the largest 2^ inches) filled with a fluid, and 

 smaller cavities similarly filled were very common. The liquid was 

 water with some carbon dioxide. Unfortunately the collection of crys- 

 tals was left exposed on a cold night, and the result was the freezing of 

 the inclosed water and consequent shattering of the crystals, a coherent 

 mass of fragments and cementing ice being obtained. 



The occurrence of rare minerals in Amelia Countj 7 , Virginia (alluded 

 to in theEeport for 1882), has been the subject of a paper by W. F. Fon- 

 taine (Amer. Jour. ScL, xxv, 330). Earlier accounts of some of the 

 minerals have been published by other writers, but the complete de- 

 scription of the locality is now given for the first time. The minerals 

 were found near Amelia Court-House, in excavations in coarse granite 

 veins made for the purpose of obtaining mica. The relations are much 

 the same as at other localities in granite veins, so that the locality 

 furnishes no very new points of general interest except the individual 

 minerals it affords. The most noteworthy of these are allanite, found 

 in thin-bladed crystals, sometimes 15 inches long; microlite,in modified 

 octahedral crystals of, for this species, very remarkable size (one mass 

 weighed 4 pounds); mouazite, in rough crystals, in one case weighing 8 

 pounds; helvite, in granular particles and indistinct crystals; colum- 

 bite, in masses of 6 to 8 pounds. There are also beryl, fiuorite, garnet, 

 and rarely a few other species. 



The very remarkable occurrence of cryolite and other fluorides in Col- 

 orado, described by W. Cross and W. F. Hillebrand, has been mentioned 

 on an earlier page. A new topaz locality in Colorado has been described 

 by the Rev. R. T. Cross (Amer. Jour. ScL, xxvi, 334). It was discovered 

 by Walter B. Smith near Platte Mountain, 25 miles north of Pike's Peak. 

 A pocket in decomposed albite yielded upwards of 100 crystals and 



