Wild Guess What Type Of Rock This Is?

[kac]

It is fairly heavy for it's size, I'll try to figure out the density. Magnets are attracted to it and I can see a couple sparkles of some crystalization but haven't cut it open as I need to get a diamond blade for my tile saw.

 

[Hardtimehermit]

Looks like magnetite, try a streak test and see if it is black, if so probably magnetite.

[Valens Legacy]

Nice looking rock and it could magnetite or granite. How big is it, or better yet do you have a picture of the whole rock.

The bottom picture looks like the backside of a axe from some of the Indians from Maine.

[Steve Herschbach]

Magnet attested to it screams magnetite, or a rock with very high magnetite content. I have a few large doorstops of pure magnetite, and they attract a magnet as if the were steel plate. If yours is less magnetic, it could be a high magnetite content basalt rock, or an ultramafic rock with high magnetite content.

[nebulanoodle]

Breaking it with a hammer v. slicing it can give you some good ID clues too. 

[kac]

Black streak.

Weight was 266g, displaced 100ml.

[GB_Amateur]

So specific gravity is 2.66?  With measurement uncertainties taken into account this measurement alone is consistent with, what, 75% of all rocks?  (Just my WAG...)  Definitely not pure magnetite, though (s.g. = 5.17).

The mystery continues....

I'm curious what kind of a signal (if any) your Garrett Sea Hunter (PI, right?) gives.

[kac]

Found with the Tejon. I run my sensitivity really high so it will pick up on some rocks and tiny coal etc. You should be able to do the same with your Vaquero, just crank it up and back it off till the chatter just stops. It will find the tiniest targets that way, good for earings etc in tot lots.

[Rick N. MI]

I find a lot of rocks like that in northern Michigan. My detectors hit them all and they're magnetic too. I have kept them all. Upper peninsula of Michigan mines a lot of iron and copper.

[kac]

Ran it under my other machines since I never found a chung that big. On the Garretts it is 38-40 both AT Pro and Apex which is the high end or iron range. On the Multi Kruzer normalized scale it's 15 which is one over the iron range.

Oddly that should have discriminated out on the Tejon but only if I run the sensitivity at the minimum. When I raise the sensitivity all the way to 10 or higher the magnetite breaks at the foil mark. Running the break that high I eliminate large iron nails but oddly can still pick this up clearly. Anyways top end of iron range on this one, should have a nice smooth tone to it.