BUILDING AND ORNAMENTAL STONES. 523 



Granite. A rock consisting of quartz, orthoclase, and mica or other accessory min- 

 erals; In the stone-cutter's nomenclature no distinction is made between the 

 varieties ; all stones which are hard, granular, and crystallized are called gran- 

 ite. 



Granitoid. Thoroughly crystalline and massive, like granite. 



Granular. A term applied to rocks composed of distinct grains, whether fragmental 

 and water worn or crystalline. 



Greenstone or griinstein. A term formerly used to designate certain basic eruptive 

 rocks occurring in the form of dikes. Through mistaken notions regarding their 

 true nature and from a general similarity in their appearance the name was 

 made to include a variety of compact, dark-greenish or nearly black rocks, 

 which microscopic examination has shown to bo priucipally diabase and dio- 

 rite. 



Grit. Any sharp, gritty sandstone or schist used as a whetstone or hone. 



Grub-saw. A saw made from a notched blade of thin iron, and provided with a 

 wooden back. Used with sand for sawing stone by hand-power. (See Plato v.) 



Guys. Ropes or chains used to prevent anything from swinging or moving about. 



Hackly fracture. A term applied when the surfaces of a fracture are rough and 

 jagged. 



Joints. Divisional planes which divide the rock in the quarry into natural blocks. 

 There are usually two or three nearly parallel series called by quarrymen 

 end joints, back joints, aud bottom joints, according to their position. (See 

 section F.) 



Ledge. Any natural solid body of rock. 



Lewis hole. The Lewis * hole consists of a series of two or more holes drilled as 

 closely together as possible, and then connected by knocking out the thin par- 

 tition between them, forming thus one wide hole, having its greatest diameter 

 in a plane with the desired rift. Blasts from such holes are wedge-like in 

 their action, and by means of them larger and better-shaped blocks can be 

 taken out than would otherwise be possible. This style of hole is saidt to 

 have been devised by a Mr. Joseph Richards, of Quincy, though at about what 

 date we are not informed. This same gentleman was also the inventor of the 

 bush hammer, which, however, when first patented, about 1831, consisted of a 

 solid piece, instead of several pieces bolted together as now. 



Limestone. Under this term almost all the calcareous quarried rocks, whether frag- 

 mental or crystallino, are classified. 



Liver rock. This term is applied to that variety of the Ohio sandstone which breaks 

 or cuts as readily in one direction as in another. In other words', the working 

 of the stone is not affected by stratification. 



Lyonaise marble. A local term applied to marbles which are composed of a mixture 

 of red and white colors, as those of Mallet's Bay, Vt. 



Marble. Any limestone or dolomi tc capable of being polished and suited for orna- 

 mental work. 



Massive; unstratified. Having, no definite arrangement in layers or strata, but the 

 various ingredients being thoroughly commingled, as in granite and diabase. 



Nigger head. (1) The black concretionary nodules found in granite; 



(2) Any hard, dark, colored rock weathering out into rounded nodules or 

 bowlders; 



(3) Slaty rock associated with sandstone. A quarryman's term. 

 Oolite. A stone composed of small globules resembling the roe of a fish. 

 Ophiocalcite. A mixture of serpentine and limestone. 



* This word is spelled by some Louis, 

 t Potter's History of Quincy, Mass. 



