Two rock questions.

[ghost surf]

1.What type of rock would be magnetic and not leave a streak mark?, other then a meteorite.
2. I hear you can take a rock and crush the particles and then on white paper see what color is left behind and geologists call that also a streak.When I do that to this rock I found it just looks like dirt you would find from grinding that you would sweep off t,he floor so....whats the best method.I all ready know this rock does not streak no-matter what I do on a streak board.I see corundum Ruby, Saf-ier leaves a white streak.My rock does not and it is magnetic.What should I do next?


All the rocks on this foto are magnetic, except the seven small rocks at the top of the picture.


This is the rock I am talking about with the dot under it.

 

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[cavers5]

Hi,

Did you ever find out anything?

Cavers5

 

[aussco999]

Hey Ghost Surf:

I didn't see your post for rock testing any earlier and maybe you already have the answer, but I'll pass along some rock testing info to be helpful. A streak test, along with color, luster, hardness, cleavage, parting, specific gravity, fracture, magnetic and crystal form are used in combination to try to identify minerals in the field.

A good streak test can be performed on the unglazed (bottom) side of a piece of ceramic tile. A couple pieces of cheap 4"x4" bathroom tile from Home Depot will do a lot of streak tests. All streak tests are done on a newly exposed surface of the rock, in other words you have to knock off a rock chip and streak the tile with the new surface. And keep in mind that when done alone, a streak test is not always a positive test for a certain mineral, but it could help you eliminate what the mineral is not. And, for all of us older and half-blind guys, alway try to examine the streak in the sunshine, maybe even with an eye loupe to get a true color.

To answer your question about magnetic metals, besides iron minerals, nickle and cobalt minerals are also magnetic. There are a couple of fairly easy chemical tests used to identify nickle and/or cobalt. If you are interested, let me know and I'll post them.

Good luck,

John

 

[Eu_citzen]

Not sure if this helps but oh well look -----> http://www.minerals.net/mineral/sort-met.hod/streak/streak1.htm<----
http://www.webmineral.com/ is good if you have more info, look at aussco999's post.
GOod luck!