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780 MINERAL RESOURCES.
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gave to Mr. W. S. Vaux, of Philadelphia, and they are now at the Academy of Natural Sciences. He suggests that they are derived from the beds of clay which are exposed in the bluff forming the southern bank of the creek. There are Cretaceous clays nearer Trenton than Crosswick's creek, in which occurs much fossil wood; in and on this grains of amber are not uncommon; they are usually very small and difficult to detect. The wood is soft and very recent in appearance, burning with an uncertain, flickering flame. The amber is evidently derived from the sap of the wood.
The late Professor Kerr(a) mentioned the finding of succinite in lumps of several ounces weight in Pitt county and elsewhere, in the Tertiary marl beds of the eastern counties of North Carolina.
Dr. Troost(b) mentions that at Cape Sable, on the northern side of Magothy river and western shore of Maryland amber of several varieties occurs. One is entirely opaque in concentric zones of every shade of red, yellow, and brown, thus displaying the most beautiful colors; another is a transparent yellow, and another is an earthy porous variety. It is found here in the lignite beds in some quantity. It also occurs on the Chesapeake and Delaware canal in Kent county, Delaware.
Mr. C. G. Yale, of San Francisco, California, says that amber is common in the lignite deposits on the peninsula of Alaska. It is also obtained in the alluvium in the delta of the Yukon river and in the vicinity of most of the Tertiary coal deposits on the Fox islands, being everywhere an article of ornament with the natives, who carve it into rude beads.
At no American locality is amber found of commercial value, and although the specimens above referred to are all called amber, they are undoubtedly, with the exception of the Nantasket amber, all from different trees from those producing the Baltic amber, and analyses of them would prove of considerable interest.
Jet.—Jet occurs in the Wet Mountain valley, Trinchera mesa, southeast Colorado, and in the coal seams of most coal-bearing rocks of Colorado. The beautiful specimens of El Paso county, although sold largely for specimens, are very little if at all used for ornamental purposes, from the fact mainly that although this perhaps rivals any known jet, black onyx has almost entirely superseded this material in the United States, owing to the greater hardness of the onyx and the cheapness with which it is furnished from Oberstein and Idar.
Meerschaum.—Sepiolite, or meerschaum, has occasionally been met with in compact masses of smooth earthy texture in the magnesia quarries in West Nottingham township, Chester county, Pennsylvania. Only a few small pieces have been tound, but they were of good quality. It also occurs in grayish and yellowish white masses in the serpentine near Stamp's tavern, in Concord township, Delaware county.
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