Anyone know what this rock is?
- Thread starter cecc
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Is it magnetic?
If not, it could be a granite that's been baked. It has the character of something that's flowed like a vein too and had time to cool slowly in its centre to make some larger crystals
If not, it could be a granite that's been baked. It has the character of something that's flowed like a vein too and had time to cool slowly in its centre to make some larger crystals
Looks like it could be a type of red granite.
kawman
steve wardle
meteor??? 
Christos57
Chris
are they crystals inside ??
looks a bit like one of the rocks on here https://twitter.com/SouthMeteorites
looks a bit like one of the rocks on here https://twitter.com/SouthMeteorites
Done a bit more reading. Not discounting anything else but the following seems a pretty good match:mbasko said:
Saprolite (weathered granite) - most pieces are stained rusty red or coated with a dark red crust. Like red granite if you look closely, you'll see pink, grey, & even darker, purplish crystals. Common in SE Qld.
No worries - might have given you a bum steer when I said common in SE Qld though. Not sure why I thought I had read that but it's more common in various areas from about Central through Northern Qld.
Seeing as though a granite belt runs through the Darling Downs region of SE Qld the presence of saprolite wouldn't surprise me at all.
I think that's how I gave you the bum steer - Darling Downs being SE Qld & Darling Ranges in WA which is a common saprolite area + was mentioned in the info I was reading :8
Seeing as though a granite belt runs through the Darling Downs region of SE Qld the presence of saprolite wouldn't surprise me at all.
I think that's how I gave you the bum steer - Darling Downs being SE Qld & Darling Ranges in WA which is a common saprolite area + was mentioned in the info I was reading :8
From what I just browsed mbasko it seems saprolite could be anything between the top soil and *bedrock* that's weathered away.
I've seen similar granite here by the decomposing stuff, ceccs though seems that it was a very hot blob for the sedimentary / rock it intruded to metamorph somewhat onto as an outer layer , possibly it was moist ( ancient river? ) and as it dried the outer layer formed the cracks? Like a puddle drying up
I've seen similar granite here by the decomposing stuff, ceccs though seems that it was a very hot blob for the sedimentary / rock it intruded to metamorph somewhat onto as an outer layer , possibly it was moist ( ancient river? ) and as it dried the outer layer formed the cracks? Like a puddle drying up
Saprolite can't be just anything between bedrock & top soil. It is formed when igneous &/or metamorphic rocks are exposed to humid climates forthousands or even millions of years.
In this case, to me, it appears to resemble the saprolite of the weathered igneous rock known as granite & in particular possibly red granite (as mentioned above & also mentioned not to discount anything else as it's pretty hard to get accurate identification from photos). Also touched on above - Saprolites are commonly formed from weathered granite & as it weathers some of the original minerals, like mica,feldspars, etc. are transformed intonew minerals, like iron oxides thus the rusty looking outer layer.
Saprolitic layers are usually just above unweathered bedrock & below the more decomposed laterite layer + soil layers. In some areas saprolite outcrops & these outcrops will more than likely have the rusty outer layer.
The exact make-up of saprolite is dependant on the weathered igneous or metamorphic parent rock - again my guess is possibly granite or more specifically red granite. My guess is that what appears to be "cracking" is just part of the weathering process & appearance over the many thousands or even millions of years that this weathering process has taken place.
Granite being igneous then yes that is a given - it was very hot at some stage many moons ago & this may have contributed to the "cracked" appearance?
I am just having a stab in the dark though from the pic.
Maybe granitic saprolite or granitic saprock may have been a more descriptive stab in the dark?
In this case, to me, it appears to resemble the saprolite of the weathered igneous rock known as granite & in particular possibly red granite (as mentioned above & also mentioned not to discount anything else as it's pretty hard to get accurate identification from photos). Also touched on above - Saprolites are commonly formed from weathered granite & as it weathers some of the original minerals, like mica,feldspars, etc. are transformed intonew minerals, like iron oxides thus the rusty looking outer layer.
Saprolitic layers are usually just above unweathered bedrock & below the more decomposed laterite layer + soil layers. In some areas saprolite outcrops & these outcrops will more than likely have the rusty outer layer.
The exact make-up of saprolite is dependant on the weathered igneous or metamorphic parent rock - again my guess is possibly granite or more specifically red granite. My guess is that what appears to be "cracking" is just part of the weathering process & appearance over the many thousands or even millions of years that this weathering process has taken place.
Granite being igneous then yes that is a given - it was very hot at some stage many moons ago & this may have contributed to the "cracked" appearance?
I am just having a stab in the dark though from the pic.
Maybe granitic saprolite or granitic saprock may have been a more descriptive stab in the dark?
Cheers for the explination mbasko - I'm surrounded by intrusive granites of all sorts from fine grained to pegmatites and weathered / acid worn etc and never seen anything like cecc's one. I've only seen similar cracking in VERY old ( 3mil years i think it is ) morphed sedimentary at Yea, VIC. Mabey the granite needs to intrude a certain ground at temps etc..all to create that outer shell. Its very new to me though ( on granite )
This nearly makes sense considering a lot of brisbane type ground I think is Triasic?
This nearly makes sense considering a lot of brisbane type ground I think is Triasic?
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mbasko said:
This is red or pink granite that has even the purplish crystals you mentioned.
We have plenty of it around, must have come down from Canada during the ice age, part of the glacial till.
Looks like mine is a carved stone, probably of Native American origin.
