Editing Theophrastus (section)

=== On stones ===
In his treatise ''On Stones'' ({{lang|grc|Περὶ λίθων}}), which would become a source for other [[lapidary (text)|lapidaries]] until at least the [[Renaissance]],{{sfn|Walton|2001|pp=359–364}} Theophrastus classified rocks and gems based on their behavior when heated, further grouping minerals by common properties, such as [[amber]] and [[magnetite]], which both have the power of attraction.<ref name="Cuvier1830">{{harvnb|Cuvier|1830|pp=76–83}}.</ref><ref>{{harvnb|Richards|Caley|1956|p=238}}.</ref><ref>{{harvnb|Caley|1956}}.</ref>

Theophrastus describes different [[marble]]s; mentions [[coal]], which he says is used for heating by metal-workers; describes the various [[ore|metal ores]]; and knew that [[pumice|pumice stones]] had a [[volcanic]] origin. He also deals with precious stones, [[emeralds]], [[amethysts]], [[onyx]], [[jasper]], etc., and describes a variety of "sapphire" that was blue with veins of gold, and thus was presumably [[lapis lazuli]].<ref name="Cuvier1830" />

He knew that [[pearls]] came from [[shellfish]], that [[coral]] came from India, and speaks of the [[fossilized]] remains of organic life.<ref name="Cuvier1830" /> He also considers the practical uses of various stones, such as the minerals necessary for the manufacture of glass; for the production of various pigments of paint such as [[ochre]]; and for the manufacture of [[plaster]].<ref name="Cuvier1830" />

Many of the rarer minerals were found in mines, and Theophrastus mentions the famous [[copper]] mines of [[Cyprus]] and the even more famous [[silver mine]]s, presumably of [[Laurium]] near [[Athens]] – the basis of the wealth of the city – as well as referring to [[gold mines]]. The Laurium silver mines, which were the property of the state, were usually leased for a fixed sum and a percentage on the working. Towards the end of the fifth century BCE the output fell, partly owing to the [[Sparta]]n occupation of [[Decelea]] from {{circa | 413}} BCE. But the mines continued to be worked, though [[Strabo]] ({{circa | 64}} BCE to {{circa | 24}} CE) records that in his time the tailings were being worked over, and [[Pausanias (geographer)|Pausanias]] ({{circa | 110}} to {{circa | 180}}) speaks of the mines as a thing of the past. The ancient workings, consisting of shafts and galleries for excavating the ore, and washing tables for extracting the metal, may still be seen. Theophrastus wrote a separate work ''On Mining'',{{sfn|Laërtius|1925|loc=§&nbsp;44}} which – like most of his writings – is a [[Lost literary work|lost work]].

[[Pliny the Elder]] makes clear references to his use of ''On Stones'' in his ''[[Naturalis Historia]]'' of 77 AD, while updating and making much new information available on [[minerals]] himself. Although Pliny's treatment of the subject is more extensive, Theophrastus is more systematic and his work is comparatively free from fable and magic,{{sfn|Healy|1999|pp= 17–7}} although he did describe [[lyngurium]], a gemstone supposedly formed of the solidified urine of the [[lynx]] (the best ones coming from wild males), which featured in many lapidaries until it gradually disappeared from view in the 17th century.{{sfn|Walton|2001|loc= abstract & throughout}}
It is mistakenly attributed to Theophrastus the first record of pyroelectricity. The misconception arose soon after the discovery of the pyroelectric properties of [[tourmaline]], which made mineralogists of the time associate the ''[[lyngurium]]'' with it.<ref>Earle R. Caley and John F.C. Richards, ''Theophrastus: On Stones'' (Columbus, Ohio: Ohio State University, 1956), page 110, line 12 of the commentary: "Watson identifies the ''lyngounon'' of Theophrastus with tourmaline, but evidently his opinion is partly based on the attractive properties of heated tourmaline which had recently been discovered. This identification is repeated by various later writers. For example, Dana states that ''lyncurium'' is supposed to be the ancient name for common tourmaline. However, the absence of tourmaline among surviving examples of ancient gems is clearly against this view."</ref> [[Lyngurium]] is described in the work of Theophrastus as being similar to [[amber]], capable of attracting "straws and bits of wood", but without specifying any pyroelectric properties.<ref>Earle R. Caley and John F.C. Richards, ''Theophrastus: On Stones'' (Columbus, Ohio: Ohio State University, 1956), page 51, paragraph 28 of the original text: "It [''smaragdos''] is remarkable in its powers, and so is the ''lyngourion'' [i.e., lynx-urine stone] … . It has the power of attraction, just as amber has, and some say that it not only attracts straws and bits of wood, but also copper and iron, if the pieces are thin, as Diokles used to explain."</ref>