b'Pyritethe firestoneFeatureFigure 2.Fire making implements from a Bronze Age burial site in Scotland (sketched by Evans 1897) used about 5000 years ago to ignite tinder. The hand held pyrite nodule hemisphere is struck with the flint bar to generate hot sparks.Figure 4.tzi man was recovered in 1991 from a glacier in the Austro-Italian Figure 3.A fine to medium grained pyrite nodule such as the sample fromAlps. Over 5000 years ago this shepherd used pyrite and flint, found on his Hunan China (left) easily generates good sparks when struck by flint, quartz, orperson (reconstructed here), to make fire. tzi man reconstruction /https://very hard steel, but the coarse grained lump of Peruvian pyrite (right) does not. commons.wikimedia.org/wiki/File:Oetzi_the_Iceman_Rekonstruktion_1.jpg / CC BY-SA 3.0energy warms the pyrite (the heat mainly dissipates) and dislodges tiny fragments with fresh faces and very reactiveHoover (1950) in their translation of the 1556 edition of the sharp edges which are not passivated and react exothermicallyGerman George Agricolas monumental De Re Metallica remark with oxygen and moisture in the atmosphere (see equation,in a Book 5 footnote:Table 1). Suitable tinder is ignited by a shower of rapidlyThe subject of pyrites is a most confused one; the term originates oxidising, very hot, clearly visible sparking particles. from the Greek word for fire, and referred in Greek and Roman times The glacier entombed mummy of a man who lived 5000 yearsto almost any stone that would strike sparks. By Agricola it was ago was found in 1991 in the tztal Alps of southeast Austriaa generic term in somewhat the same sense that it is still used in (Figure 4). This late Stone Age/early Copper Age man carriedmineralogy, as, for instance, iron pyrite, copper pyrite, etc. So much a flint knife, a copper axe, and pieces of flint and pyrite forwas this the case later on, that Henckel, the leading mineralogist percussive fire-making. of the 18th Century, entitled his large volume Pyritologia, and in it embraces practically all the sulphide minerals then known.Pyrite in the ancient and medieval world The cubic mineral pyrite, FeS 2 , is so spectacular in its splendid crystalline form that it easily draws the attention of a casual Pyrite was recognised as an iron sulphide by Germanobserver. It is not uncommon and it presents quite a contrast mineralogists in the early 1700s. Before that, it was a collectiveto the average drab, dun appearance of most rocks. It is noun for yellowish metallic sulphides (Table 2). Hoover andrather odd that pyrite seems never to have been directly and DECEMBER 2019 PREVIEW 54'