Rocks, Minerals & Fossils photo game

muckish

Post a photo of a specimen you have collected/bought. Or a locational shot with a distinct geological/geomorph feature in it. Test the knowledge of other posters.

Here's one to start:

Step23

Hard to tell from the photo but I'd say Azurite or Lazurite. I can see what appears to be carbonate on the rock already.

muckish

Lapis Lazuli from Afghanistan. Correct. Azurite might have had a bit of malachite whereas Lazurite is commonly mixed with Pyrite.

Step23

Close enough

I have attached a specimen I have collected myself. Its probably not that hard to guess what it is.

muckish

Step23 wrote: »

Close enough

I have attached a specimen I have collected myself. Its probably not that hard to guess what it is.

That's a beauty. Where di you pick that one up? My first thoughts were Olivine but now I think it may be green tourmaline.

Step23

muckish wrote: »

That's a beauty. Where di you pick that one up? My first thoughts were Olivine but now I think it may be green tourmaline.

I should have mentioned I found it in Ireland, that would rule out Green Tourmaline (as only schorl (the black iron rich varity) has been found in Ireland), Olivine would be a good guess, but the matrix being vein quartz rules this out. The mineral is Pyromorphite, a lead chloro phosphate. I found it in the Wicklow lead mines.

Good guess though!

muckish

That's a stunning mineral. Will definitely have to look out for that. cheers

agardiner22

Step23 wrote: »

Close enough

I have attached a specimen I have collected myself. Its probably not that hard to guess what it is.

that is a stunning rock...one of best i have seen from ireland

agardiner22

how do u show pics in the posts

muckish

agardiner22 wrote: »

how do u show pics in the posts

you need to host your photo first on a photo sharing site such as flickr or picasa. those site will have a sharing option which will give the html or BB code for the image's location. Copy the code bit that starts with http://www.... and ends with .jpg etc. Paste this inti the insert image option in your boards post.

muckish

Another one I picked up at a rock shop in Austria. More a structural one than what mineral is this!

Step23

Nice example. My guess is dendritic manganese oxide!

muckish

Step23 wrote: »

Nice example. My guess is dendritic manganese oxide!

I bought it for the dendritic structure and forgot to ask about the mineralogy. You're probably right on the manganese though.

Step23

Any thoughts what this one is?

Hardness 4-4 1/2
No Cleavage and a Hacky Fracture.
It has a higher specific gravity than Galena.

Clue: the surface has tarnished.

I wish this pieces was mine but it's not, so any ideas what it is?

muckish

Silver?

Step23

Sort of close, it is a native element! But its platinum.

muckish

Ha ha I can see now why you wish it was your! cheers

El Siglo

Here's an XRD trace of one of my samples, anyone know what mineral is with the high peak? (It's a pretty common mineral that tends to mess up XRD results, such as the 200 odd that I've analysed).

slowburner

This looks like a thread that I could lurk around very happily.
I hope you guys keep at it. I live in an area very rich in minerals and seeing rocks that you identify and that are familiar to me could be very rewarding indeed.
I know nothing at all about geology but I'm surrounded by interesting lumps and a huge variety of them. I'll play the game by posting the odd pic and let you identify the type - I hope you'll let me play

muckish

slowburner wrote: »

This looks like a thread that I could lurk around very happily.
I hope you guys keep at it. I live in an area very rich in minerals and seeing rocks that you identify and that are familiar to me could be very rewarding indeed.
I know nothing at all about geology but I'm surrounded by interesting lumps and a huge variety of them. I'll play the game by posting the odd pic and let you identify the type - I hope you'll let me play

Go for it.

As for the XRD trace mineral. Is it calcite?

El Siglo

muckish wrote: »

Go for it.

As for the XRD trace mineral. Is it calcite?

Ohhhh, I'm afraid not. I'll give you a clue, it's silica based and associated with an igneous rock.

kearneybobs

El Siglo wrote: »

Ohhhh, I'm afraid not. I'll give you a clue, it's silica based and associated with an igneous rock.

I can only presume it's a feldspar of some sort. Plagioclase?

El Siglo

kearneybobs wrote: »

I can only presume it's a feldspar of some sort. Plagioclase?

So very close, it's quartz.

slowburner

This boulder sticks out amongst a field of granite erratics - there are a few more about the place but this is the only one I was able to clean up. The others are in a nearby stream and heavily discoloured.
This picture was taken while the rock was wet.

This one was taken when it was a bit dryer.

slowburner

Schist?

slowburner

This a section through a material which I thought might be an old concrete. It was found in the bed of a stream.
Could it be some kind of conglomerate?

muckish

slowburner wrote: »

This boulder sticks out amongst a field of granite erratics - there are a few more about the place but this is the only one I was able to clean up. The others are in a nearby stream and heavily discoloured.

Not too sure from the photos, but it sort of looks like a granite contact zone breccia. Are the pale spotty parts granite, similar to the grantie boulders around?
The vein structure \ is interesting as it seems to be post rock formation. Also the second set of linear structures // seem to be original bedding from the original Host? rock. Interesting Boulder alright. What's the location generally?

slowburner

muckish wrote: »

Not too sure from the photos, but it sort of looks like a granite contact zone breccia. Are the pale spotty parts granite, similar to the grantie boulders around?
The vein structure \ is interesting as it seems to be post rock formation. Also the second set of linear structures // seem to be original bedding from the original Host? rock. Interesting Boulder alright. What's the location generally?

There's no granite in the boulder. These two pics might give a bit more detail. The veins are not 'quartzy' if you know what I mean, more like a chalky substance.

donzenettii

Step23 wrote: »

Close enough

I have attached a specimen I have collected myself. Its probably not that hard to guess what it is.

Wow, that is beautiful

Step23

donzenettii wrote: »

Wow, that is beautiful

Glad you like it. Its one of my favourite specimens in my collection.

Here is another for you's to guess what it is.



Specimen is from Glendalough and is about 11cm long.

slowburner

With regard to the conglomerate pictured above: it turns out that it is pebbles from the stream bed cemented together with iron oxide - according to an eminent geologist.