THE ONYX MARBLES. 571 



one side with a variety of colors and peucilings that make a very fair 

 counterfeit of the real first-class article, after which the side that is 

 painted is covered with a coatinj^- of very tine cement, which gives it 

 the appearance of having been merely sawed and left unpolished. 

 This class of work is often done so w^eil that when first finished it will 

 deceive any but the sharpest of experts, but under a year or two of use, 

 the swindle becomes apparent, and soon nothing remains but a thin, 

 transparent slab of stone. 



The formation in which tlie marble or onyx is found is a tough, red- 

 dish or dark-brown clay, overlying a closely cemented conglomerate. 

 This is the usual form, but in one instance — that of the Antigua 

 Salines, on the liancho del Carmen — it is found in a hard. Hint-like 

 country rock which appears to be more of a bastard jasper than any- 

 thing else. In this instance the onyx appears as a regular vein 

 formation, the veins varying from 1 to 12 inches in width. 



Of the quarries themselves all are small. The most famous — La 

 Pedrara, in the district of Tecali, 21 miles from the city of Puebia — 

 does not cover more than 3 acres, while the average depth of the 

 quarrying is not over 7 feet. The value of the onyx taken from this 

 small area, though, is hard to realize. The high leputation of the stone 

 is recognized the world over, but it is very doubtful if one-tenth of 

 what has been sold as "■ La Pedrara" during the last quarter of a cen- 

 tury ever came from it. At i)resent no attempt is made to work the 

 quarry, in fact no indication of onyx in the place is to be seen; the 

 only effort made in obtaining onyx from it being by sorting over the 

 old dumps or refuse places which have accumulated during its active 

 existence. From these is taken every piece of onyx that will square 

 6 inches or over. The process is slow, while the yield is seemingly 

 Aery small in return for the labor. The onyx obtained is of a very fine 

 quality of green, ranging from a very light to a very dark tint, and, 

 as a rule, showing a slight dash of red or pink. Occasional pieces of 

 variegated colors are found which are very tine, while the texture is 

 very good. 



Xext in inq)ortance to La Pedrara is AntUjua iSaJiiies, in the district 

 of Tehaucan, and which has already been briefly mentioned on account 

 of its peculiar geological formation. The quarry covers over an area 

 not exceeding two acres, and forms the face of a hill about 250 feet 

 high. lu working it, the system has been simply a process of gouging 

 out the onyx and the rock which encases it, until into the side of the 

 hill there has been excavated a hole 100 feet in width by 50 feet in 

 height and 00 feet deep, looking very much as if an immense shovelful 

 had been taken out. The onyx is variegated in colors, and is ranked 

 next to La Pedrara. 



Ranking third, probably, in importance is La Sojiresa, which covers 

 an area of about 5 acres, and is located about So miles west of Antigua 

 Salines, in the same district. The onyx from this quarry is semitrans- 

 hicent, white, totally devoid of colors, save where an occasional mass 



