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The Jeffrey mine is in operation since more 100ans. It is a Welsh slater, name of Evan Williams, who was the first to raise the presence of asbestos in the area in 1880. Following this discovery, it persuades a rich person farmer, W.A. Jeffrey to advance the funds necessary to him for the development of the layer located on a hill, one was in 1881. In 1895, because of problems financier, W.A. Jeffrey yielded his interests to a group to associate to form in 1897 the company Asbestos and Asbestic Company. In 1916 the mine became the property of Manville Asbestos Company later, reorganized two years under the corporate name Canadian John-Manville Company, Limited, which exploits the property since then. Today nothing any more remains of this hill because the exploitation with open sky of the layer makes more than 0.7 km in diameter by approximately 0.45 km of depth. If one examines the photograph (vertical cut), one notices a ophiolitic zone entitled complex (marked with X). This zone contains rocks such as; peridotite, dunite, unquestionable pyroxenite, gabro and intrusive rocks in association. The 2 types of rocks which interest the owners finds in the peridotite and the dunite serpentinized by fibre chrysotile veins. But for me and my companions they are rather the intrusive rocks which draws our attention when that we have access in the mine. The intrusive rocks term, indicates the formation of rock which very required by the collectors is tested of the Jeffrey mine. They forms many mass irregular resembling filon(dykes) whose composition varies granite with diorite without forgetting the albitite and the rare tràs rodhingite. This for saying that it is starting from these famous filons(dyke), intersecting the rocks serpentinized, that it is formed by hydrothermal deterioration. Garnet grossularite, hessonite, diopside, prénhite, vésuvianite and mangavésuvianite, let us be all the persons in charge of the reputation of the Jeffrey mine. One has to inventory more than one about sixty minerals different in the mine. Therefore I will exempt yourself of all to you to enumerate them àà the exception of those, which in my opinion not nothing to envy the world elite. Aragonite, apophylite, nemalite (VAr brucite), chrysotile, clinochlore, pectolite, wollastonite. The company with recently invested in the underground browsing and all seems to carry to believe that the exploitation with open sky draws at its end. If it is the case, from here a few years, it will be very difficult to recover specimens as those which marked the mineralogical world at the end of the Seventies and in the middle of the Eighties. However, each years the mine reserves beautiful surprises to me as testifies garnets pink to them to the summer 1998. The year 1999 does not seem to want to save either bus in May to me I updated, at the court of a rock with rodhingite, my more beautiful lucky find with life. Taking my courage with 2 hands, for the chisel and the other for the mass of 5lbs, I pickled approximately 70cm very hard rock to update a massive diopside vein. When the vein was finally released (1 day later) I endeavoured to release a sterile section in the vein using my small mass and of my chisel. It is at this time that I had the surprise of my life bus of only one blow of mass my chisel had been just inserted 8cm in the vein. By releasing a small part on the top I then found myself vis-a-vis with a black hole, exciting mysteagrave;re unexplainable, but it is only by removing a second piece of the vein, to make it possible in the light of the day to enter, that my heart with fact 3 turns and half. In made, I came to update an immense pocket of approximately 40 X 17 X 50cm, covered with splendid diopside crystals green. As if that were not sufficient nature made grow on the floor of this pocket of the garnet crystals perfect hessonite gem, of which largest reached 1.4cm, the whole impaled on diopside.  grenats chromifère sur prénhite    Coupe de la mine Jeffrey  grenats grossulaires var. hessonite grenat grossulaire var. hessonite grenats chromifère |