570 REPORT OF NATIONAL MUSEUM, 1893. 



notable sights connected with a tour of Mexico are tlie magnificent 

 collections of articles of this marble which are to be found in many 

 churches, particularly that in the cathedrals of the cities of Mexico and 

 Puebla, and in the churches of Leon, Queretaro, and Guadalajara, 

 several of which contain perfect slabs 3 and 4 feet square, an extraor- 

 dinary size on account of the small and irregular shape iu which the 

 stone is found. 



During recent years fashion has taken up what the ])riests of these 

 two religions thus marked with their approval, and the stone under the 

 name of Mexican onyx, with its capricious markings, has become so 

 well known as to make a detailed description of its different varieties 

 unnecessary. To those who have made its acquaintance, though only 

 through the medium of the ordinary onyx table top, clock, or the 

 interior ornamentations of public buildings, beautiful as such are, it 

 Avould be hard to convey a correct idea of the exquisite beauties of the 

 tiner grades of the marble. While the ordinary grades commonly 

 encountered probably surpass iu elegance any similar material, it is 

 oidy in the light and dark green, the ivory-colored, the brilliantly 

 banded, and the dark-red varieties that a full realization of the stone 

 at its best is had. 



iu the quarries the stone is found iu the form of detached masses, 

 ranging in size from a few inches up to 10 or 12 cubic feet. Larger 

 sizes are occasionally found, but so rarelj^ that the event is a notable 

 one, while the value per cubic foot is correspondingly increased. For 

 example, the value of a piece containing 1 or 2 cubic feet would be 

 estimated to be ordinarily $3 per cubic foot iu Mexican money, but 

 were the piece to contain 25 or 30 cubic feet, the valuation would be 

 about $15 j)er cubic foot. This is for ordinary stock; with green and 

 the other finer grades it would be very difficult to form any estimate 

 whatever. This smallness of available sizes is one of the principal 

 defects of the stone, and one with which the best skill has battled in 

 vain. With its other defects, that of occasional fiaws or holes, ranging 

 from a tenth of an inch to 2 or 3 inches iu diameter, more success has 

 been had iu remedying the negligence of nature by filling the smaller 

 with a cement mixed with powdered portions of the stone, while in the 

 larger a piece of the onyx is very often boldly inlaid with such skill as 

 to defy detection on a cursory inspection. With the growing inability 

 to supply the demand for onyx, this last method of making the most 

 out of what remains of the stone has been pursued to a great extent, 

 and with very good success except where the article so "improved" is 

 subjected to sudden changes of tempeiature, in which case the effect 

 of our northern climate at once becomes apparent, and the best of 

 work under the irregular processes of expansion and contraction soon 

 becomes unsightly. Almost as common but a more questionable 

 method of "improving" the stone is that of sawing the inferior qual- 

 ities that lack color into very thiu slabs, so thin as to be almost 

 translucent. These are then operated on by an "artist," who adorns 



