FMF - Friends of Minerals Forum, discussion and message board

[chz9392000]

I guess its hardness is around 5.5 because it may scratch the glass plate, depending on the force I applied. I have a feeling of sandy texture however not very sure. I guess sandstone is generally softer. Any help is appreciated.

[Bob Carnein]

Where is it from? Correctly identifying a rock such as this is difficult, even for a trained geologist who has the rock in front of them. Even then, a microscopic examination of a thin section may provide the only means of confirming the ID. Pictures are often misleading. If you know where it was collected, you may be able to find a reference on the geology of that area that includes a map showing distribution of rock types. This would help in narrowing down the identity.

[Herman van Dennebroek]

At first sight your specimen looks like sodalite. But as Bob mentioned it's very difficult to determine from a photo

[chz9392000]

Hi all,

Thanks very much for your responses! Unfortunately, I don't know its place of origin.

[Josele]

Could be a mafic igneous rock, gabbro type for example.

As said, without proper analysis is not possible to classify a rock with precision.

Bob gives a good clue with the geological map when it is easily affordable in your country.