Dr. Troost on Amber, ^c. 



Art. III. — Description of a variety of Amber, and of a 

 Fossil Substance supposed to be the nest of an Insect dis- 

 covered at Cape Sable, Magothy River, Ann-Arundel 

 County, Maryland; by Doctor G. Troost, of Balti- 

 more.. 



Thk Amber found at Cape Sable is either perfectly 

 Opaque, of the colour exhibiting every shade of a mixture 

 of yellow, grey and brown, sometimes so arranged in near- 

 ly concentric zones as to display the most beautiful colours, 

 admired in the Egyptian Jasper, (quartz agathe onyx of 

 Haiiy,) or disposed in alternate bands, dots, spots, clouds, 

 each as in the other agates and jaspers. It resembles also, 

 often the mastich or gum sandarac, occurring in that case al- 

 ways as this gum resin does in tears, and is then wax or hon- 

 ey yellow : sometimes with a tinge of brown, and sometimes 

 reddish yellow or hyacinth red. The transparent variety 

 occurs seldom. It is again translucent, resembling near- 

 ly, in this case, in its external appearance, the resin or colo- 

 phony. The lustre of some is very considerable, and of 

 others, particularly of some of the opaque varieties, is dulL 

 It breaks easily, exhibiting a perfectly conchoidal fracture, 

 and is of the same hardness with the amber of the Baltic. 



Its specific gravity varies from 1,07 to 1,180. This dif- 

 ference is no doubt owing to small particles of pyrites, with 

 which the cavities are sometimes lined. 



Some specimens have only a slight degree of electricity, 

 whilst others possess this property in a high degree. 



It is susceptible of a good polish. 



2d Variety. Earthy Amber. This usually occurs in 

 fragments or friable porous masses, of the size of a walnut, 

 having a dull earthy aspect intermixed with pyrites. Its so- 

 lidity does not exceed that of clods of loam or of a stiff 

 soil, with which, externally, it has some resemblance, an4 

 like this, crumbles by friction between the fingers. Its 

 colour is gray or yellowish gray like ashes — by exposure to 

 heat it melts, gives out the smell of common amber, and 

 has then all the properties of the common melted amber. 



The first variety of amber occurs in grains, and in de- 

 tached pieces, from the size of a mustard seed to that of 

 pieces fi-ora 4 to 5 inches in diameter. Its external surface 



