English: Plate XXIV, Figure 2 of 1898 publication called Maryland Geological Survey Volume Two. Caption:
Slate Quarry, Ijamsville, Frederick County
The text which refers to this figure is as follows:
At the present time no slate is quarried at Ijamsville although this locality has been known as a source of slate for nearly if not quite a hundred years. Parrish, in his brief history of the slate trade in America, states that quarries near Frederick were opened about 1812. This may be a reference to the small openings at Linganore but it seems more in harmony with local traditions to infer that the quarries about Ijamsville were in mind.
When Tyson prepared his report, there were two slate quarries in operation. One was situated just west of the railroad station beside the tracks and the other was about a half mile south of the town. They were evidently quite small for they had not reached the best material. Little work was done during the time of the Civil War and the more prominent quarry shown in Plate XXIV Fig 2 was permanently abandoned about 1870 when the pit commenced to undermine the roadbed of the Baltimore and Ohio Railroad. The smaller opening lying south of the town never attained any considerable importance although efforts were made as late as 1892 to bring the product of this quarry into the market. The method of working followed was that of the Germans who mine rather than quarry their slate. A shaft was sunk to a depth of about sixty feet but the enterprise was not successful.
The slates from Ijamsville formerly brought nearly as good prices as those from Harford county but at the present time they are almost unsaleable. This is not due to the poor or unstable character of the stone so much as it is to the relatively poor workmanship displayed in recent years and the popular demand for a slate which will ring when tapped with a finger or pencil. Because of the hard and compact character of the better siliceous slates from Pennsylvania and the northern states it has become customary to regard all dull or soft slates as untrustworthy. In many instances this view is correct but in the case of the Ijamsville slates it is not warranted by the facts. The slates from this locality show microscopically that they are well crystallized and that they do not owe their softness to a partial change from a shale to a slate but to an admixture of the relatively stable and soft mineral talc, which is usually wanting in the better known slates. If the stone were unstable the blue-black color would change upon exposure. This it does not do since roofs on which the slates have been exposed to the atmosphere for fully fifty years do not indicate any change in color as a result of this exposure. In spite of their permanency in color and their strength the slates have yet to prove themselves a basis for a profitable industry.