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Robson Vieira
Joined: 05 Jan 2017
Posts: 14
Location: São Paulo


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Posted: Aug 18, 2018 16:18 Post subject: Mineral ID help. |
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Hi everyone. I found some amygdaloidal basalt samples in a basalt quarry and one of the pieces has an acicular mineral among some Analcime. It was not possible to perform tests in order to identify such mineral, because it is small, brittle, and is in a difficult location on the stone, into the Analcime geode.
If you can help me with the identification, I would thank you a lot.
Regards from Brazil
Mineral: | Analcime Association |
Description: |
Cuesta Basaltica, São Paulo 9,5 x 7,0 x 5,0 cm Unknown acicular mineral with Analcimes |
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Viewed: |
1825 Time(s) |

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Mineral: | Analcime Association |
Description: |
Cuesta Basaltica, São Paulo 9,5 x 7,0 x 5,0 cm Unknown acicular mineral with Analcimes |
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Viewed: |
1827 Time(s) |

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Mineral: | Analcime Association |
Description: |
Cuesta Basaltica, São Paulo 9,5 x 7,0 x 5,0 cm Unknown acicular mineral with Analcimes |
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Viewed: |
1829 Time(s) |

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Mineral: | Analcime Association |
Description: |
Cuesta Basaltica, São Paulo 9,5 x 7,0 x 5,0 cm Unknown acicular mineral with Analcimes |
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Viewed: |
1830 Time(s) |

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Tom Tucker
Joined: 03 Dec 2009
Posts: 54
Location: Virginia


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Posted: Aug 18, 2018 16:49 Post subject: Re: Mineral ID help. |
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Looks like mesolite, or related needles. Can you give the quarry location ? Thank you, Tom
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Nick_G
Joined: 04 Apr 2018
Posts: 10
Location: Whitchurch, Hampshire


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Posted: Aug 18, 2018 16:49 Post subject: Re: Mineral ID help. |
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It looks like natrolite to me, which is found as acicular crystals in amygdaloidal cavities on basalt. The cavities are formed from expanding gas bubbles in the cooling rock, which then get filled with other minerals such as calcites and zeolites.
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Justin Hickok
Joined: 28 Sep 2017
Posts: 66
Location: Strasburg


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Posted: Aug 18, 2018 16:57 Post subject: Re: Mineral ID help. |
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As usual I'm probably wrong but I guessed millerite. 😬
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John Betts
Joined: 07 Jun 2012
Posts: 123
Location: New York City


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Posted: Aug 18, 2018 17:02 Post subject: Re: Mineral ID help. |
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Of the acicular white minerals associated with analcime, natrolite is more likely than mesolite or scolecite. Definitely NOT millerite.
_________________ John Betts |
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Bob Harman
Joined: 06 Nov 2015
Posts: 468
Location: Indiana



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Posted: Aug 18, 2018 17:07 Post subject: Re: Mineral ID help. |
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Agree with JOHN B, definitely NOT millerite.
Why? Because not only is the geologic setting wrong for millerite, but blowing the photo up shows the acicular needles to not be silvery/brassy metallic as they should be with millerite (NiS).
And JUSTIN, I really suggest you sit back, not post, but just read what is being said and learn from others with more experience and knowledge. BOB
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Justin Hickok
Joined: 28 Sep 2017
Posts: 66
Location: Strasburg


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Posted: Aug 18, 2018 17:38 Post subject: Re: Mineral ID help. |
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Actually I think many folks here have become complacent and rather pompous. And I think maybe some of you would be better off in a private forum.
It seems to me you would rather talk amongst your professional selves than actually teach.
And that's fine. Its your forum!
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Robson Vieira
Joined: 05 Jan 2017
Posts: 14
Location: São Paulo


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Posted: Aug 18, 2018 20:23 Post subject: Re: Mineral ID help. |
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Thanks for all. I had thought it could be both natrolite and/or scolecite, but is difficult to decide. The exact location is the very little and unkown town of Terra Roxa, São Paulo, Brazil. It is in the north of the state, in a geological district called "Cuesta Basaltica", where basalt and related predominate.
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Robson Vieira
Joined: 05 Jan 2017
Posts: 14
Location: São Paulo


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Posted: Aug 18, 2018 20:28 Post subject: Re: Mineral ID help. |
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20°45'04.8"S 48°24'00.5"W, exact location coordenates.
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John S. White
Site Admin

Joined: 04 Sep 2006
Posts: 1236
Location: Stewartstown, Pennsylvania, USA



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Posted: Aug 19, 2018 05:20 Post subject: Re: Mineral ID help. |
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Justin. I want to apologize for Bob's rudeness. That is not typical of the responses that you should get from members of this Forum and I am very sorry that this occurred. Please don't give up on this forum.
John
_________________ John S. White
aka Rondinaire |
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Jordi Fabre
Overall coordinator of the Forum

Joined: 07 Aug 2006
Posts: 4227
Location: Barcelona



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Posted: Aug 19, 2018 07:28 Post subject: Re: Mineral ID help. |
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John S. White wrote: | Justin. I want to apologize for Bob's rudeness. That is not typical of the responses that you should get from members of this Forum and I am very sorry that this occurred. Please don't give up on this forum.
John |
But at same time, Justin, if you are not sure about what the mineral could be, maybe it would be better to not post anything, at least for a while, because if you jump in at the start it tends to introduce confusion on an already confusing task. Determining a mineral species just by a photo and without any testing is a not easy and very uncertain question ;-)
Thank you.
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Matt_Zukowski
Site Admin
Joined: 10 Apr 2009
Posts: 614
Location: Alaska



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Posted: Aug 19, 2018 08:37 Post subject: Re: Mineral ID help. |
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I think John was right to call Bob Harman out on this. Bob simply should not have called Justin out like this without PMing Justin and the admins of this forum. But Bob H is also a good member of this community and should be supported. I think the solution is a mutual understanding. Bob H should be more constructive in his methods to improve this forum we value. But at the same time Bob H should ABSOLUTELY not take this as a slight because I know I speak for all of us when I say that Bob has shared with us loads about Midwest minerals specifically, and other good things, and I want him to be a part of FMF. I value Bob Harman’s contributions to FMF.
Justin, I think I know where you are buddy. When I found a forum of like-minded mineral geeks, I totally wanted to jump right in. Over time I learned that I learned more when I let the threads build up on their own. I think I have found ways to contribute, and I think your enthusiasm, should you choose to express it here with us, will lead you places to contribute too. Lurk around for a while. I think you will find it is worth it.
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