After the rain I went rock hunting and found this unique rock .....

[Daprezident661]

Need someone's knowledge to help identify this rock. Your time and input is highly appreciated..
The Rock is heavy for its size and it's smooth all around, kind of looks like a bunch of rocks just melted together

 

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[DDancer]

Appears to be a water worn granitoid, a river cobble stone. The appearance of multiple rocks melted together is due to the different hardness's and erosion of the stones various minerals. My thoughts.

 

[Daprezident661]

Thank you for your information..I truly do appreciate you taking the time to help me out !! For minute there I thought nobody was able to help me out if you can I have plenty of other rocks and minerals I would like to get help on identifying them and if there of any value I will definitely share a piece of the earnings with you if sold .... ?

 

[yakker]

Na- it isn't about the money- let's see what you have though! Yakker

 

[Daprezident661]

Na- it isn't about the money- let's see what you have though! Yakker

I'm not sure what kind of rock it is but it has a bunch of diamond like crystals inside of it .. The rock is real Heavy and hard to break.. The outer surface of the rock is smooth and shinny with a oily like feel and the inside of the rock is rough with many diamond like crystals ... O and when put under a UV light parts of the rock glow for a moment after turning off light, like a fluorescent paint. View attachment 1101916 View attachment 1101919 View attachment 1101920 View attachment 1101922 View attachment 1101923

 

[DDancer]

Yakkers got it~ not in it for the money just the rocks
You posted about that fluorescing stone in another thread here. What color/s were present?

 

[yakker]

Those attachment pics aren't the same rock at the top of your post- right? Looks like tiny little quartz inclusions in the close-ups but I'm not certain. Maybe someone else will take a look. HH Yakker

 

[woof!]

Referring to the one at the top of this thread: heavy and dark color suggest ultramafic. Doesn't seem macrocrystalline enough to be a granitoid. Heavy as well as the lack of porous texture suggest not volcanic extrusive, more likely intrusive or metamorphic. The greenish color looks olivine'ish. The black, possibly pyroxene? if it bothers an ordinary compass a lot, then there's a lot of magnetite in it. The mottling is the result of recementing of a breccia, suggesting metamorphism although this can happen in fault zones of materials of other types.

In one photo we see striations, which although associated with surface texture irregularity appear to be part of the rock structure. This would represent either a shear zone or depositional layers. In the context of this particular rock, it's a shear zone.


I vote for a recemented metabasalt breccia. If there are known greenstone belts in the vicinity, that'd pretty well nail it. If not, well, time for some other opinions (one coming up soon).

If you've got a compass handy, see if it deflects the compass more than just a tiny amount. If it does, as a minimum the rock is ultramafic and contains substantial magnetite. This looks like an easy rock to measure SpeeGee on if you know how, and that'll tell you roughly what the iron content of the rock is (although it won't tell you what minerals the iron is part of).

SECOND OPINION: This is a river cobble. The roundness of the thing indicates that apart from some small-scale texture, the rock is of uniform hardness and toughness and that it is well-cemented with material that's probably just about the same as the bulk of the brecciated material. And the surface is polished. There's only one good candidate, and that's quartz. The rock probably would have formed within a hydrothermal fault zone that included quartz intrusions cutting through mafic or ultramafic country rock, the quartz having been colored by the country rock and probably containing a lot of more complex silicates. The pitting would result from formation of crystals either softer or more chemically weatherable, that were insoluble in the quartz matrix. If the pits are square, the mineral in question was iron sulfide. If not square, the mineral was likely something else.


* * * * * Your turn, EU Citizen......... vad ni tanker?

 

[DDancer]

HAAHHHH! woof indeed

 

[Eu_citzen]

LOL ok, the first one.

The dark colour suggests mafic to ultramafic, the greens and blacks suggest pyroxene and/or amphibole perhaps even serpentine.
The lighter colour (quartz? Feldspar?) could indicate metamorphism. Some vein like formations of the green also suggest metamorphic.
I'll just guess a more plastic deformation.


So that makes it a metabasite, perhaps amphibolite.