162 SOUTHERN BORDER OF CENTRAL COAL FIELD. 



ARAGONITE. 



This mineral was found by me in only two localities in sufficient quantity 

 to be of any use; yet I do not doubt that it can be found in other localities 

 equally as abundant as at the places mentioned below. 



One of these places is on the lands of Mr. D. N. McRea, about fifteen miles 

 west of the town of Lampasas, near the north line of Burnet County. It 

 occurs in a fissure in the massive limestone of the Carboniferous formation. 

 It is very compact and much of it is beautifully banded. Some of it when 

 fractured has a dark resinous color. It takes an excellent polish, and can be 

 obtained in slabs large enough for table tops. 



Another locality is in San Saba County, on the south side of Cherokee 

 Creek, five or six miles from its mouth. This has about the same geological 

 position as at the former locality, and the material is about the same as that 

 from Lampasas County, only it seems to be a little whiter and the crystals are 

 smaller. This material is used largely for making ornaments, and is generally 

 known when polished as " Mexican onyx." It is not an onyx, but is simply 

 a carbonate of lime crystalized under a peculiar form. It does not differ in 

 composition from calcite. 



STRONTIANITE. 



This mineral is found in beautiful crystals on the head of Little Lucy 

 Creek, six miles north of the town of Lampasas, and elsewhere in that vicin- 

 ity. It also occurs at the head of Lynch's Creek, twelve miles northwest of 

 the town of Lampasas. 



At both these places it is imbedded in the limestones of the Cretaceous 

 formation. It is found on Lucy Creek at two horizons about twenty feet 

 apart. In the lower it is in massive nodular form, and is in a bluish lime- 

 stone. At the upper horizon it occurs in geodes, with crystals of dog-tooth 

 spar. Some of the crystals are beautifully tinged with blue, and are almost 

 perfect crystals. Other crystals are clear white. This mineral is used in the 

 manufacture of nitrate of strontia, which is used for making red color in fire- 

 works. One nodule was obtained weighing forty-three pounds. 



Another locality where this mineral was seen was near the head of Lynch 

 Creek. It occurs in this place also in the Cretaceous formation, and is asso- 

 ciated with crystals of calcite. None of the material at this place had the 

 beautiful blue tinge that gives value to the crystals for cabinet specimens. It 

 is probable, however, that such crystals might be found upon diligent search. 



BUILDING STONE. 

 There is an abundance of building stone in all the counties, and in nearly 



