rock crystal were given the same generic name. Pliny105 alludes to the existence of books which contained directions for staining quartz in imitation of smaragdus and other precious stones, a fraud, he remarks, that was more lucrative than any other. Seneca106 also mentions the staining of stone to resemble smaragdus. The Stockholm Papyrus, which contains numerous recipes for the imitation of precious stones by the staining of rock crystal, shows that there was a substantial basis for these remarks. According to this papyrus,107 green precious stones were counterfeited by applying copper salts and organic coloring materials to quartz after its surface had been roughened. Rock crystal colored in this way could not have passed for a clear transparent green stone like emerald, though counterfeit stones of this kind may well have been a tolerable imitation of translucent green quartz. Whether such imitations passed for natural stones is uncertain, but the wording of the recipes indicates, at least, that they were known by the name smaragdos without qualification. Since the recipes given in the papyrus for imitating this particular stone are about equal in number to all the recipes for imitating other kinds of stones, it is clear that these counterfeit green stones were frequently used by the ancients.
■23. it ma\es the color of water just like its own. This supposed property of smaragdos is not mentioned by any other ancient writer, though Pliny108 in a somewhat analogous passage remarks that from a distance such stones appear larger than they really are, because their green color is reflected by the surrounding atmosphere. Some commentators have supposed that this statement of Pliny was based on a misinterpretation of the present passage in Theophrastus, and King109 even supposed that Pliny's account represents the original sense of the Greek passage, and that ύδατος ("water"), which now appears in the text, is a corrupt reading for aepos ("air"). Actually, the statement of Pliny is so different that it is unlikely that he paraphrased or even used
105 XXXVII, 197.
loe Epistulae Morales, 90, 33.
107 O. Lagercrantz, Papyrus Graecus Holmiensis (Uppsala, 1913), pp. 7-8, 11-13, 14, 19-21, 22, 23-24, 165, 174, 176, 177, 179, 182-83, '93> 194» 195» Ϊ96-97. 199-200. ίο» XXXVII, 63. 109 Natural History of Precious Stones and of the Precious Metals, p. 280.
