Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: Vadermort on 28/08/2006 03:36:04

Title: Rock Identification for my Essay
Post by: Vadermort on 28/08/2006 03:36:04
I need some help with identifying these rocks.
Can anyone help me?

Rock 1
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock1.jpg&hash=e92b3d363a3fba7e6a3b7672753168d5)
Rock 2
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock2.jpg&hash=848218e637a6f605f8fcba579e93b8b6)
Rock 3
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock3.jpg&hash=95e7ff7c4544b288410bece3c64cb524)
Rock 3 closer
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2Fobsidian.jpg&hash=bdb7acb7a85d2148e1d2b59775c48a40)
Rock 4

b.s
Title: Re: Rock Identification for my Essay
Post by: Bass on 28/08/2006 04:46:49
your pictures are not entirely clear- could you add a description?  Are you studying metamorphic rocks?
Can you measure hardness, or see bedding or foliation?  Can you identify any of the minerals (quartz, mica, feldpar, amphiboles)?
Here's a real shot in the dark-
1.  looks like either quartz or calcite veining, the left hand side of the rock appears to have micaceous minerals- if so I would guess gneiss or biotite schist?
2.  Quartzite? Gneiss?  Mylonite?
3.  Muscovite schist?  black is probably biotite, white is either feldspar, quartz, or rock fragments.

With more information, I could possibly provide a more accurate identification and geologic processes.

Subduction causes orogeny.
Title: Re: Rock Identification for my Essay
Post by: Vadermort on 28/08/2006 06:15:19
Thanks for the help anyways. There are more pictures here. Unfortunately my camera got stolen after taking better pictures so im using a webcam.

Rock 4
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock4.jpg&hash=55fddc9f05ea35bf85270bdf218508c2)
This rock is flat and smooth with brown areas on it
Rock 4 closer
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2Fbrown.jpg&hash=8ebb1579bc3ad446d04b10209a233f64)
These are the brown areas
Rock 5
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock5.jpg&hash=fb18c1b020f4c1061e55f211c9b73623)
Looks like limestone with white insides. I will do chem. testing soon
Rock 6
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock6.jpg&hash=34c8e07e0261434d7684760434724e3e)
Sorry for unclear image. It apears to have some pattern on the side that could be biological?
Rock 7
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock7.jpg&hash=dab8e3ebfc2e708d6894acb777ac579f)
Rock 8
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock8.jpg&hash=bcbfd142e330d3a233fedf3a3f82ac52)
I think this is just quartz.
Rock 9
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock8.jpg&hash=bcbfd142e330d3a233fedf3a3f82ac52)
This rock is shiny on both sides.
Rock 9 Closer under light
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FShiny2.jpg&hash=be06983aef980a06e630aee1dd8096c9)
Rock 10
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FShiny2.jpg&hash=be06983aef980a06e630aee1dd8096c9)
Thanks.. no time have to go.

b.s
Title: Re: Rock Identification for my Essay
Post by: Vadermort on 28/08/2006 06:23:57
Sorry..
Rock 9 is this rock
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock9.jpg&hash=bc704044f541aba496e53d1286844b2d)

Rock 10 is this
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi100.photobucket.com%2Falbums%2Fm8%2Fvadermort%2FRock10.jpg&hash=586170f0af2110a362f7afca0c0675bb)

Sorry for the confusion. Im very busy right now...Its ok ill check up all the rocks that it could be. The shiny on rock 3 is not muscovite. It looks shiny because it is under a light.

b.s
Title: Re: Rock Identification for my Essay
Post by: Bass on 28/08/2006 17:55:10
4:  Brown areas are probably iron oxide (limonite)- hard to tell much else from the picture
5:  let me know after you check with acid
6:  possible shale/argillite/slate (depending on degree of metamorphism)
7:  gneiss? quartzite?  marble? (hard to tell much from photo)  can you recognize any minerals in the rock?
8: I think you are correct- looks like quartz
9:  muscovite schist
10:  Looks like quartz or calcite veining in the photo- do the veins fizz in acid?  What is the hardness?

Throw me a bone here- a bit more information.  Are you trying to identify these for a geology class?  If so, what types of rocks (sedimentary, igneous, metamorphic) are you studying?  do the rocks scratch easily- only slightly- or not at all?  Are there any distinct crystals?  have you tried acid (don't forget, if the rock is dolomite, you need to scratch the rock before you get a reaction- fizz)?  is there a distinct layering in any of these rocks?

Subduction causes orogeny.
Title: Re: Rock Identification for my Essay
Post by: Vadermort on 29/08/2006 06:16:20
Im a high school geography student. Not much of a geologist. These rocks came from a rock quarry in southern China and are probably metamorphic and sedimentary rock. There are crystals present in rocks, 1(black) 3(black) 9 (small and goldish) 8(the quartz) All rocks except 9 scratch easily. the others are harder than fingernail. I will do chemical tests with each rock this evening and get back to you in about 12 hours. I will be doing precipitation with NaOH for iron, and HCl acid for carbonates. Any ideas of other chemical tests?

b.s
Title: Re: Rock Identification for my Essay
Post by: Vadermort on 30/08/2006 09:40:59
Testing with sodium hydroxide is done. Rock 9 made a white precipitate indicating either magnesium or Calcium, the latter more likely. There was a very small trace of green precipitate in rock 4 which indicates the small presence of iron. Thats all that hapened. the rest didnt have any precipitate.

b.s
Title: Re: Rock Identification for my Essay
Post by: Vadermort on 30/08/2006 09:40:59
Testing with sodium hydroxide is done. Rock 9 made a white precipitate indicating either magnesium or Calcium, the latter more likely. There was a very small trace of green precipitate in rock 4 which indicates the small presence of iron. Thats all that hapened. the rest didnt have any precipitate.

b.s