Amber (FR., Ambre, Succin, Carabe; GER., Bernstein, Agtstein).—Amber is a fossilized resin yielded by trees that are auppose,d to have grown upon the greensand beds of the Cretaceous forma tion, the forest originally reaching probably from Holland over the German coast, through Siberia and Kamschatka, even to N. America. The tree affording this resin, an extinct species of pine, has been provisionally named Pinites succinifer, but GrOppert has proved that the product is not necessarily from a single species, nor even confined to the Coniferce at all.
The amber aupply obtained from the Baltic region of Prussia is more important than the com bined contributions of all other districts. In W. Prussia, the resin is found not only in the sea and on the shore, but also in a minor degree in the hilly interior. In the latter case, however, "nests " are rare, and the yield and profit of the scattered diggings are trifling. E. Prussia, and especially the part called Samland, is the great amber-producing centre. Here, particularly at Wansen, Lassen, Groskuhren, Klienkuhren, Kraxtepellen, Kreislacken, Hubnicken, and Palrnnicken, amber mining is a settled industry. The productive stratum is a " blue earth," a loose, bluish sandstone, the lower member of the marine Tertiary formation of the locality. It has a thickness of 8-28 ft., the lowest 7-114 ft. alone being worked. The depth is 108 ft. below the surface, and 46 ft. below sea-level. The ground is worked by shafts and levels, in the ordinary way, but with extraordinary precautions against inrushes of sea-sand and water. The ground as picked down is sent to surface, and there undergoes examination. This consists in washing it with water through a long inclined trough, whose entrance is barred by a grating of 21---3-in. apertures, to arrest large masses, which require careful breaking by hand. Men armed with nets are stationed at 6-ft. intervals along the trough, and pick out all valuable pieces. The " tailings " or waste from the trough escapes through a 0.315-in. sieve into the sea. Recently, jigging-machines have been introduced in lieu of the troughs and net-men. Their sieves have a gauge of 0.118 in., through which the earthy matters are washed, leaving the amber on the surface. These machines (20) pass 350 cwt. of earth an hour. The average output of the mines is 15,000-25,000 tubs (of about ton) a month, yielding 60-120 cwt. of large, and 22-36 cwt. of small amber, the former embracing all sizes from 100 gr. to 21 lb. The cost of production is estimated at 43.-6s. 6d. a lb. The mean yield of amber is I kilo. (2.2 lb.) for every 20 cub. ft. excavated. The average local value is placed at Is. 3d. a lb. for small, and 7s. 6d. for large. In the three years 1876-8, the total production from about 13 acres of this ground (some 160 acres have been proved or worked) was 208/ tons of large and 60i tons of small amber, with a total value of 174,350/. The working is a monopoly of the Prussian govern ment, who received in royalties for that period 44,661/.
The area of the amber-bearing stratum of E. Prussia is far from being satisfactorily determined.
11/loreover, there is reason to believe that other strata exist at deeper levels than tbe oue now being worked, as considerable quantities of the resin are found among soil washed away by the sea, during heavy gales, from those portions of the coast sand-hills that lie at a lower horizon. This is known as flicsen amber, in contradistinction to the erd amber of tbe mines ; it is softer and of less uniform colour. This marine amber is obtained by dredging at Schwarzort, on the Kurische Haff, near Memel, and by diving at Briisterort. The yield of the former is of considerable importance, amounting to 80,000-90,000 lb. annually. The resin is found almost uniformly in separate nodules, with lignite, disseminated in the sand, at a depth of 10-12 ft. The dredged-up sand is sent ashore, and washed in the same way as the earth from the mines. The production of amber in E. Prussia in 1870 was 1415 ewt., of which, the dredging at Schwarzort contributed 740 ewt.; the diving at Briisterort, 300 owt.; the mines in Samland, 55 ewt.; the fishing along the coast, 320 cwt. This was mueli below the average, in consequence of the war. In 1874, some 360,000 lb., of all sizes and qualities, were exported.
The occurrence of amber outside the German empire is very trivial and precarious, and the products are said to be of different origin. Stray pieces occasionally found on the coasts of Norfolk, Suffolk, Essex, and Sussex, and on the Swedish and Danish shores, usually after severe storms, are doubtless washed from the Baltic beds. It sometimes occurs in the sandy deposits of the London clay at Kensington, and associated with bituminous deposits ha the Paris clay ; also in the French departments of Aisne, Loire, Gard, and Bas-Rhin, as well as near Basle, in Switzerland. The shores of the Adriatic and the coasts of Sicily likewise afford specimens; those from the latter often havo a green or violet-blue colour. Some years since, an extensive bed of yellow amber was dis covered in sinking a well near Prague, aud pieces weighing 2-3 lb. were produced. Roumania possesses amber-deposits in the mountains of Sibicio, Valley of Bugeo, which, rationally exploited, might become important. The prevailing colour of the produet is brown, but all shades occur, from orange-yellow or red to black, blue, and green, sometimes with specks and veins of several tints. The supply is always diminishing in quantity and in the size of the pieces. ln N. Burma, amber-beds are found at an elevation of 1050 ft., to the S.-NV. of the Mien Khortn plain, in the Hukong Valley. Pits are sunk to a maximum depth of 40 ft., the lower half penetrating a grayish black carbonaceous earth. American localities where amber is met with are Cape Sable, near Magothy River, Maryland ; Gay Head, near Trenton, and Camden, New Jersey ; and, more rec,ently, near Vincentown, New Jersey. All the specimens are found in the greensand formation. The sp. gr. of the Vincentown amber is less than that of water.