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Ferrous Dolomite...or?
  
  Index -> What is it? - Where is it from?
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Bergur_E_Sigurdarson




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PostPosted: Aug 29, 2018 15:31    Post subject: Ferrous Dolomite...or?  

Got a bunch of these from a guy in Chiquinquira. His sources are in Boyaca, but no more details on location in this case.

I have more but those pictured range from 2-6cm in the largest way.
(I already packed them down for my trip back home to Iceland, so no more exact sizes at the moment, sorry)

Don't look much like what I know already from Colombia... shapes are slightly curved, but many edges/corners have added angled parts... as shown in closeup of second picture.

Comparing to what I could find in mindat.... and by what I've seen in mineral shows... it looks a bit like ferrous dolomite... except for those angles on near the edges...
...the colour is unlike any dolomite I've seen in Colombia... closer to the baryte colour from there
...they are not transparent enough... so... not sure if inclusions are causing colour or what.



ferrous-dolo-001.jpg
 Mineral: Ferrous Dolomite?
 Description:
Boyaca
2-6 cm
 Viewed:  1132 Time(s)

ferrous-dolo-001.jpg



ferrous-dolo-002.jpg
 Mineral: Ferrous Dolomite?
 Description:
Boyaca
appx 1,5cm x 2,5cm
 Viewed:  1129 Time(s)

ferrous-dolo-002.jpg


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alfredo
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PostPosted: Aug 29, 2018 15:39    Post subject: Re: Ferrous Dolomite...or?  

Siderite could be possible too. Check how magnetic it gets after heating in a kitchen gas flame.
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Fiebre Verde




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PostPosted: Aug 29, 2018 16:00    Post subject: Re: Ferrous Dolomite...or?  

Alfredo's guess is correct.
This is indeed siderite which can be found close to Muzo.
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Fiebre Verde




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PostPosted: Aug 29, 2018 16:40    Post subject: Re: Ferrous Dolomite...or?  

Here is a siderite specimen from the same locality


siderite.JPG
 Mineral: Siderite
 Locality:
Muzo mining district, Western Emerald Belt, Boyacá Department, Colombia
 Description:
 Viewed:  1083 Time(s)

siderite.JPG


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Bergur_E_Sigurdarson




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PostPosted: Aug 29, 2018 16:41    Post subject: Re: Ferrous Dolomite...or?  

Awesome.... thank you so much guys!

That specimen of yours Gerard is so alike... must be the same locality indeed :-D

I looked siderite up on mindat... and matches fairly perfectly... even has the angle on the corner in the crystal-diagram :-)
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