blende rock ; but the more beautiful and highly prized variety is due to transmutation from dolomitic limestone. This variety occurs in the form of bands and laminae, often twisted and tangled, of varying shades of green, from deep sap-green to translucent pale yellowish-green, and interlaced with bands of white calcite, or crystalline dolomite. Sometimes speckled or mottled varieties, exhibiting a quasi ‘ eozonal’ structure, occur. The principal quarries are at Lissoughter Hill, Recess, Ballynahinch, and at Streamstown, between Clifden and Letterfrack. 1 When used with discretion, and sparingly, amongst light masonry, this stone is displayed to the best advantage ; but the effect of a large surface devoid of other materials for the sake of contrast, is not pleasing to the eye ; nor does it withstand the influence of a smoky or gaseous atmosphere. The effect both of the internal and external use of the Connemara marble is well shown in the new Museum of Trinity College, Dublin. 2 Co. Donegal. Foliated green serpentine, with bands of calcite, or dolomite, occurs at Crohy Head; and a denser, olive-green variety, is found at Ang- 1 Specimens may be seen in the hall and galleries of the Royal College of Science, Dublin. 2 Small tablets let into the outside wall of the Museum have become tarnished within the space of ten years. Within, the columns which adorn the hall of the building have retained their polish.
