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Pete Richards
Site Admin

Joined: 29 Dec 2008
Posts: 842
Location: Northeast Ohio



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Posted: Dec 23, 2019 16:29 Post subject: Re: Specs of white shiny magnetic metal - are they iron, nickel or chalcopyrite? |
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Bob Carnein wrote: | (snip) It appears to have a conchoidal fracture, which would rule out galena. |
In fact, galena has perfect cleavage in three directions, like salt. Any loose particles of your mineral should look like little blocks with all right angles if it's galena.
And galena is not attracted to a magnet....
_________________ Collecting and studying crystals with interesting habits, twinning, and epitaxy |
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GabiG
Joined: 21 Dec 2019
Posts: 19
Location: United Kingdom


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Posted: Dec 24, 2019 05:01 Post subject: Re: Specs of white shiny magnetic metal - are they iron, nickel or chalcopyrite? |
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Thank you again! :-) You give me so much information. I'm very grateful! I am going to crush one of the smaller rocks and try separate all the metal elements as best I can. Then I will try what you suggest.
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GabiG
Joined: 21 Dec 2019
Posts: 19
Location: United Kingdom


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Posted: Dec 25, 2019 09:13 Post subject: Re: Specks of white shiny magnetic metal - are they iron, nickel, or chalcopyrite? |
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I have now tried the scratch test against a stainless steel knife. Some isolated mineral crumbs from the rock sample did not scratch the knife surface when I rubbed them against the knife surface. In fact, they crumbled to almost a powder. Scratching one of the fragments with a needle caused some bits to come off the fragment. So, it’s possible to scratch this mineral with a needle. I also tried the streak test. The streak is dark grey with no hint of green. I took some more close-ups of the mineral fragments and I cannot see right angles. But the rock crushed well, so maybe the mineral fragments were also crushed too small. Anyhow, there were a couple of slightly larger ones to photograph. The magnet test showed that the fragments attached easily to even a weak fridge magnet. I think it’s ferrite but not absolutely sure. So, does that make it pyrrhotite?
Mineral: | Pyrrhotite? |
Locality: | North Laxey Mine area, Laxey, Isle of Man |  |
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Dimensions: | 2mm |
Description: |
Photo 1 of isolated Fragment 1 |
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15775 Time(s) |

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Mineral: | Pyrrhotite |
Locality: | North Laxey Mine area, Laxey, Isle of Man |  |
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Dimensions: | 1mm |
Description: |
Photo 2 of isolated Fragment 1 |
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Viewed: |
15802 Time(s) |

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Mineral: | Pyrrhotite |
Locality: | North Laxey Mine area, Laxey, Isle of Man |  |
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Dimensions: | 1-2mm |
Description: |
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Viewed: |
15799 Time(s) |

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Mineral: | Pyrrhotite |
Locality: | North Laxey Mine area, Laxey, Isle of Man |  |
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Dimensions: | 1-2mm |
Description: |
Mineral fragments together |
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Viewed: |
15783 Time(s) |

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Mineral: | Pyrrhotite |
Locality: | North Laxey Mine area, Laxey, Isle of Man |  |
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Dimensions: | 1-2mm |
Description: |
Photo 2 of fragments together |
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Viewed: |
15810 Time(s) |

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Mineral: | Pyrrhotite |
Locality: | North Laxey Mine area, Laxey, Isle of Man |  |
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Dimensions: | -1mm |
Description: |
Example of crushed rock with mineral fragments |
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Viewed: |
15761 Time(s) |

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Bob Carnein
Joined: 22 Aug 2013
Posts: 353
Location: Florissant, CO



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Posted: Dec 25, 2019 11:17 Post subject: Re: Specks of white shiny magnetic metal - are they iron, nickel, or chalcopyrite? |
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Sounds like pyrrhotite to me. Mindat includes it in their list.
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