Any rock hounds frequent this forum?

[Kainas]

It is a long shot, but I am trying to find someone who might be able to help me identify some rocks for my daughter (almost 5yo). She collects them but, aside from sandstone, I can't identify any of them. I would like to help her learn while she is interested. They are nothing special, just rocks from the ground whenever she travels anywhere (We were at Dubbo zoo and it was the rocks that she loved best... you know what kids are like).

Thanks,
Cassie.

[GPSGuided]

Hey, me too. I also had a stage when I just loved rocks. Identification is so much easier these days with the various web sites.

[icefest]

You could post images on here and see what the groupthink will bring up.

I'm not a rock hound myself, but as a group we might be able to find out a couple of them.

It's probably easier if you can remember where she found them too.

[Travis22]

I've got some family members who are strongly into gems and lapidary etc.

If you can post up an image I can pass it on for an answer.

You could also look online to see if there are any gem and lapidary clubs in your area, I'm sure your daughter would love visiting one of their clubhouses/ workshops and I'm sure they could identify any rocks she's collected.

Travis.

[Kainas]

Thank you, I will post a few pictures. I have 15 but I will offer up just a couple I think and see how it goes.

I tried the online rock identification sites, but my lack of knowledge kept seeing me end up with obviously wrong answers (I am pretty sure I know what marble looks like, and that wasn't what I had in my hand, etc).

I have contact a local gem and mineral club, but no response so far. I would feel a bit rude turning up to a meeting with my daughter and a pile of rocks, but that was what I most wanted. I had hoped someone could sit with her and explain a bit.. she is a very interested girl.

[Kainas]

Rock #1 - For some reason I just suspect this is a bit of brick. It was found in our backyard. We have in our backyard, behind our shed, 3 generations worth of rocks.. it s kind of amusing, I think they are from old gardens. We also dig up shells in our backyard all the time - my pop would throw them there (we live 2hrs inland).

Rock #2 I think this is granite?

Rock #3

[Strider]

Rocks two and three looks like basalts to me. Definitely not granite. Rock two could even be a weathered piece of dolerite.

[Pteropus]

I'm not a geologist, but have an amateur's interest in the subject. I am not sure but the first one could be a piece of ironstone. The second and third ones do look like granite and the grains are too large to be basalt (generally basalt is fast cooling, resulting in small grains, and granite is slow cooling deep underground resulting in large grains), and I'm fairly certain dolerite is only found in Tasmania and not on the mainland (but happy to be corrected Strider?).

Cassie, do you know what soil type your place is on? Are you sure the shells in the garden come from your pop? Or could be that you are on an alluvial flood plain? Anyway, just a thought.

[maddog]

My guesses are (not a rock hound):
Rock 1 (if it is not part of an old brick) Sedimentary - Conglomerate (course, rounded particles > 2mm).
Rock 2 Igneous -Gabbro (course grained, dark).
Rock 3 Sedimentary - Breccia (sedimentary, course angular particles > 2mm)

Useful classification tables:
Igneous rocks (volcanic)
Igneous rocks - minerals (%)

Metamorphic rocks - old rocks pressurised and partially melted

Sedimentary rocks - formed from compacted sediment

Last edited by maddog on Tue 30 Sep, 2014 9:45 pm, edited 1 time in total.

[Kainas]

I'm not a geologist, but have an amateur's interest in the subject. I am not sure but the first one could be a piece of ironstone. The second and third ones do look like granite and the grains are too large to be basalt (generally basalt is fast cooling, resulting in small grains, and granite is slow cooling deep underground resulting in large grains), and I'm fairly certain dolerite is only found in Tasmania and not on the mainland (but happy to be corrected Strider?).

Cassie, do you know what soil type your place is on? Are you sure the shells in the garden come from your pop? Or could be that you are on an alluvial flood plain? Anyway, just a thought.

Lots of clay soil in our area. I think one of those may have come from Dubbo Zoo (and I think a lot of that stuff came from landscape people). We have only just realised how important it is to keep notes of where the rocks are found.

Our backyard is crazy. It is a regular 1/4 acre block in Cessnock.. but today I picked up some shards of flint, and some slate, and a whole pile of river rocks behind the shed. We have a barrel of coal in a corner, and the shells were stored in the stable by my father... and they migrated through the yard, and the oyster shells are because my pop used to throw them there (lol, it was my pop's home).