Jncmud Posted May 2, 2019 Share Posted May 2, 2019 Can someone Identify what kind of rock this is? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Morlock Posted May 2, 2019 Share Posted May 2, 2019 Can you provide some details about where it was found? Have you done a streak test on it yet? Quote Link to comment Share on other sites More sharing options...
Jncmud Posted May 2, 2019 Author Share Posted May 2, 2019 I found it at work in the parking lot island that is filled with stone. I have no idea what A streak test is. Quote Link to comment Share on other sites More sharing options...
Au Seeker Posted May 2, 2019 Share Posted May 2, 2019 When Morlock asked where it was found he meant where in the world/country it was found, the local geology could help trying to ID it. A streak color test is when you rub the specimen on a piece of unglazed ceramic tile or porcelain and see what color the streak it leaves on the ceramic or if it doesn't leave a streak at all, which is rare but can be the case, this will help deciding what mineral could be, the underside of a toilet tank lid will work well to do a streak test, do 2 streak tests, one on the crust/shell and another on the bumpy interior part, as they certainly seem to be different, once you do the test/s post the color/s. Another test that would be helpful is a hardness test, starting with a finger nail and working your way through harder materials, such as copper a knife blade, metal file glass, etc. to see which will begin to scratch the specimen. You can also do a internet search for how to do both of these tests, which will explain it a bit better. 1 Quote Link to comment Share on other sites More sharing options...
Morlock Posted May 2, 2019 Share Posted May 2, 2019 https://geology.com/minerals/streak-test.shtml 1 Quote Link to comment Share on other sites More sharing options...
Jncmud Posted May 2, 2019 Author Share Posted May 2, 2019 11 minutes ago, Morlock said: https://geology.com/minerals/streak-test.shtml I just out side of Cleveland. It was mixed in with large river rock. Quote Link to comment Share on other sites More sharing options...
Bedrock Bob Posted May 2, 2019 Share Posted May 2, 2019 (edited) That is prismatic or jointed basalt. It is a really neat specimen. Rocks like these are fairly common in volcanic areas. Yours is cool because it is just the right size and nicely formed. It is natural geometric sculpture. Basalt is an extrusive volcanic or "lava". It gets prismatic like that from having just the right amount of silica in the molten mix and cooling quickly. It "cubes up" with fractures as it cools along prismatic lines. Here is an explanation. That piece looks like a "bomb" or ejecta that actually flew out of an eruption. But round basalt "bombs" will also form in volcanic mud or slurry, like a pyroclastic flow. Sometimes this stuff forms long columns when it comes out of the earth as a big flow. Check it out. This is just a wild guess. I don't know very much about rocks and stuff. Edited May 2, 2019 by Bedrock Bob They sell these rocks as oviraptor's nests or eggs on e-bay. Quote Link to comment Share on other sites More sharing options...
d_day Posted May 3, 2019 Share Posted May 3, 2019 4 hours ago, Bedrock Bob said: That is prismatic or jointed basalt. It is a really neat specimen. Rocks like these are fairly common in volcanic areas. Yours is cool because it is just the right size and nicely formed. It is natural geometric sculpture. Basalt is an extrusive volcanic or "lava". It gets prismatic like that from having just the right amount of silica in the molten mix and cooling quickly. It "cubes up" with fractures as it cools along prismatic lines. Here is an explanation. That piece looks like a "bomb" or ejecta that actually flew out of an eruption. But round basalt "bombs" will also form in volcanic mud or slurry, like a pyroclastic flow. Sometimes this stuff forms long columns when it comes out of the earth as a big flow. Check it out. This is just a wild guess. I don't know very much about rocks and stuff. I’ve never seen or heard of jointed basalt forming in such small pieces. I think it’s far more likely to be a hematite after pyrite concretion. The smooth shell breaking away to reveal the interior is pretty indicative of a concretion. 1 Quote Link to comment Share on other sites More sharing options...
Diggingd Posted May 3, 2019 Share Posted May 3, 2019 Looks like a good idea for a candy.. chocolate chips in a hard chocolate shell. Quote Link to comment Share on other sites More sharing options...
Haderly Posted May 3, 2019 Share Posted May 3, 2019 12 hours ago, d_day said: I’ve never seen or heard of jointed basalt forming in such small pieces. I think it’s far more likely to be a hematite after pyrite concretion. The smooth shell breaking away to reveal the interior is pretty indicative of a concretion. I agree. Ohio has a lot of concretions and this one looks to be a classic formation. 2 Quote Link to comment Share on other sites More sharing options...
Bedrock Bob Posted May 4, 2019 Share Posted May 4, 2019 On 5/2/2019 at 8:57 PM, d_day said: I’ve never seen or heard of jointed basalt forming in such small pieces. I think it’s far more likely to be a hematite after pyrite concretion. The smooth shell breaking away to reveal the interior is pretty indicative of a concretion. Basalt the size of softballs will cube up like that given the right conditions. It is a very common sight in my neck of the woods. It could definitely be a concretion too. Your assessment about the rind on concretions is spot on. And given the location it would be more likely. A little input from the OP on streak and density would tell the tale. If it is a hematite concretion it will be super easy to positively identify just by hefting it and abrading it a little. Quote Link to comment Share on other sites More sharing options...
Morlock Posted May 4, 2019 Share Posted May 4, 2019 A streak test will put this issue to rest. 1 Quote Link to comment Share on other sites More sharing options...
Knifemaker84 Posted May 5, 2019 Share Posted May 5, 2019 Dinosaur egg... 1 Quote Link to comment Share on other sites More sharing options...
Mike C... Posted May 5, 2019 Share Posted May 5, 2019 10 minutes ago, Knifemaker84 said: Dinosaur egg... Or fossilized Fish eggs Mike C... 1 Quote Link to comment Share on other sites More sharing options...
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