Table 1 Summary of the mineralogy of primary Au-Ag ores from Limousin (French Massif Central).
From: Geochemistry of Gold Ores Mined During Celtic Times from the North-Western French Massif Central
Ore deposit/ | Ore grades (ppm) | Ore Mineralogy (*) | |||
|---|---|---|---|---|---|
mining site | Sample Id | Au | Ag | Pb | |
Les Fouilloux (A) | 4300 | 30.6 | 6 | 233 | stibnite, pyrite, arsenopyrite, Ag-poor tetrahedrite (4.5–4.8 wt % Ag), chalcopyrite, galena, sphalerite, berthierite, jamesonite, gold with Au/Ag ratio: 86/14–80/20 |
4301 | 56.4 | 11.5 | 156 | ||
4302 | 80.6 | 9.3 | 148 | ||
4303 | 39.9 | 28.3 | 2890 | ||
4306 | 94.0 | 9.4 | 401 | ||
4453 | 82,03 | 17.4 | 308 | ||
Cros Gallet (A) | 4438 | 306.89 | 16.3 | 104 | gold, arsenopyrite, lindstromite, native bismuth; two gold populations (Au/Ag ratio): 89/11–87/13 and 81/19 |
4141 | na (**) | na | na | ||
4142 | na | na | na | ||
Cros Gallet (M, underground) | 4439 | 1105.85 | 45 | 624 | gold (Ag = 28 wt%), arsenopyrite, pyrite, galena, chalcopyrite, sphalerite, bournonite and boulangerite |
Cros Gallet (M, open pit) | 4315 | 0.31 | <0.5 | 11 | pyrite, arsenopyrite |
4316-a | 0.27 | <0.5 | 9 | ||
4320-a | 0.15 | <0.5 | 6 | ||
4321-a | 0.16 | <0.5 | 12 | ||
4322 | 0.33 | <0.5 | 10 | ||
4323 | 0.23 | <0.5 | 12 | ||
4324 | 0.20 | <0.5 | 11 | ||
4327 | 0.34 | <0.5 | 12 | ||
4330 | 0.66 | <0.5 | 18 | ||
Lauriéras (A) | 4532 | 0.32 | 5.2 | 171.74 | pyrite, arsenopyrite, boulangerite/jamesonite, chalcopyrite traces |
4534 | 0.87 | 2.4 | 491.87 | ||
4536 | 1.78 | 2.1 | 724.68 | ||
4538 | 0.22 | 0.1 | <L.D. | ||
4540 | 0.03 | 0.2 | 5.88 | ||
Lauriéras (A/M) | 4363 | 0.03 | 0.7 | 48 | pyrite, arsenopyrite |
4366-a | 0.17 | 7.8 | 337 | ||
4358-a | 9.14 | 80.5 | >10000 | ||
4541 | 12.64 | 5.5 | 26.88 | ||
4537 | 0.22 | 0.46 | 19.39 | ||
Lauriéras (M) | 4143 A | na | na | na | type 1 gold (Au/Ag = 87/13) with Ag-poor tetrahedrite, (4 wt% Ag), bournonite, boulangerite, jamesonite, galena, sphalerite, chalcopyrite and arsenopyrite |
4143 C | na | na | na | ||
4143D | na | na | na | ||
4150 | na | na | na | ||
Lauriéras (M) | 4144B | na | na | na | type 2 gold (Au/Ag = 51/49) with Ag-rich tetrahedrite (17 wt% Ag), sphalerite, chalcopyrite, galena, pyrite, and arsenopyrite |
4144 C | na | na | na | ||
Lauriéras (M) | 4149B | na | na | na | type 3 gold (Au/Ag = 75/25) with arsenopyrite |
4149 C | na | na | na | ||
Les Renardières (M) | 4337 | 0.28 | 1.2 | 15 | gold (Au/Ag = 65/35) with Ag-rich tetrahedrite (10–17 wt % Ag), pyrite, sphalerite, chalcopyrite, arsenopyrite, galena, boulangerite, jamesonite, freibergite, acanthite |
4342 | 0.22 | 1.3 | 97 | ||
La Rochefroide (M) | 4349 | 0.47 | 1.9 | 91 | pyrite |
4350 | 0.94 | 5.5 | 100 | ||
4351 | 0.93 | 2.9 | 201 | ||
