Native Coppe?^ Ores of Copper, and other Minerals. 113 



Such are the ores of copper, hitherto found in this part of New 

 Jersejr. AUhough widely distributed, they do not occur in suffi- 

 cient quantity at any one locahty, to render mining operations 

 profitable. Thousands of dollars have been expended in fruitless 

 researches, and other thousands will probably still be wasted in 

 the same manner, for in this business, the lessons of experience 

 seems to be of little avail. 



I shall notice a few other minerals found in this vicinity. 



Sulphate of Barytes. — In the slate on the banks of Law- 

 rence's brook, about two miles southeast from New Brunswick, 

 narrow veins of a kind of ochreous clay, are sometimes observed. 

 In one of these veins, which was three or four inches wide, frag- 

 ments of crystals of sulphate of barytes have been found. They 

 are translucent, have a bluish color, and vitreous lustre. Specific 

 gravity from 4.422 to 4.447. By cleavage the primary form of 

 the crystal may be obtained. 



About a mile west of New Brunswick, on the farm of I. C. 

 Van Dyke, Esq., there is another locality of the same mineral. 

 Some of the specimens are opaque, and have a yellowish color, with 

 a foliated structure. Others exhibit crystals of the primary form, 

 the right rhombic prism, which are translucent, and have a blu- 

 ish tint. Bat more frequently, they present foliee, with two sides 

 of the primary, diverging from a centre, and gradually increasing 

 in width. 



Fibrous Carbonate of Lime. — This mineral occurs in the 

 strata of red shale, about half a mile above the rail road bridge 

 at New Brunswick. The seams are from a quarter to half an 

 inch in thickness. They are in some cases at right angles to the 

 strata, and at others paralled with them. The perpendicular 

 veins are either fibrous, or semi crystalline, like a plate of zinc. 

 The horizontal layers consist of delicate and almost silken fibres, 

 translucent, and of a bluish white color. Specific gravity 2.719. 

 Soluble in nitric or muriatic acid with effervencence. 



As this mineral was supposed to contain carbonate of strontia, 

 I dissolved a portion of it in nitric acid, and evaporated the solu- 

 tion to drive off the excess of acid. To a clear solution of this 

 salt in water, I added a saturated solution of sulphate of lime, 

 but no precepitate, nor even cloudiness resulted. The sulphate 

 of lime employed in this way is, I believe, the most certain test 

 of the presence of strontia. 



Vol. XXXVI, No. 1.— Jan.-April, 1839. 15 



