[Rockhounds] Streaking (WAS: Darwin, CA Pyrite RATED PG-13)

[Kreigh Tomaszewski]

John,

You could go to the list of minerals at MinDat and look at each one 
until you found a match, or you could go to 
http://www.webmineral.com/determin/metallic_minerals_by_hardness.shtml 
and see if the hardness and streak identifies any minerals on your list 
of minerals from the locality.

Kreigh


On Friday, Dec 5, 2008, at 17:36 America/Detroit, John Siebel wrote:

> Carolyn wrote:
>>> try identifying your metallic mineral by a little streaking!!!
>
> Boy, does that remind me of my college days! What a weird fad. I could 
> tell stories but I don't know if I could stay on topic without getting 
> too lewd.
>
> Anyway, the silver mineral in this specimen streaks brown (I had to 
> double check with Julie as I am color blind). Hardness seems to be 
> about 5ish. Rules out galena and arsenopyrite yes? Again, Mindat gives 
> me these associated minerals. http://www.mindat.org/loc-3466.html
>
> Where to from here?  - John
>
> ----- Original Message ----- From: "Carolyn Reynard" 
> <sunstone3 at hvc.rr.com>
> To: "Rockhounds at drizzle.com: A mailing list for rock and gem 
> collectors" <rockhounds at lists.drizzle.com>
> Sent: Friday, December 05, 2008 11:17 AM
> Subject: Re: [Rockhounds] Re: Darwin, CA Pyrite RATED PG-13
>
>
>> Hi John,  Not bad at all! We are having a bit of fun with this one.  
>> Next,
>> try identifying your metallic mineral by a little streaking!!!
>>
>> A streak test will give you the color of the mineral in powdered form.
>> Firmly rub the mineral on an unglazed piece of tile.  Pyrite will 
>> give you a
>> greenish-black color, Galena will give you a dark gray, Arsenopyrite 
>> will
>> streak black.  Also there is a difference in hardness, Pyrite is 6 - 
>> 6 1/2,
>> Galena a 2 1/2 -3   Arsenopyrite a 5 1/2 -6. I have added Arsenopyrite
>> because it is another hydrothermal mineral.
>>
>> I'll take my bubbly in a glass!
>> Carolyn
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