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"Thomas de Groot" <t.d### [at] inter nlnet> wrote:
> "PM 2Ring" <nomail@nomail> schreef in bericht
> news:web.445210571843be3376ba2c900@news.povray.org...
> >
> > Thanks, Thomas. It's always nice to get your geologist's approval of my
> > stones.
>
> Oh hum... <grin>
>
> > Living in Sydney, I've seen weathered sandstone all my life, and plenty
> > weathered by seepage. Sydney basin is built on sandstone and shale. As
> well
> > as the white, yellow and apricot colours of my palette, the real stones
> have
> > some beautiful shades of red, ranging from pale rose pinks to an almost
> > purple colour. I know the reds & yellows come from iron, but I don't know
> > about the purple.
> >
> It very much depends on the minerals in solution percolating through. Iron
> of course, manganese like dlm says. I am not too familiar with that branch
> of the trade. The irony is of course that I am living in a country that is
> very poor in hard rock! But you can get the same kind of staining in sands
> too, especially in the older deposits from the Pleistocene. And sands are
> the building blocks of sandstones, so...
Yes, I was expecting you to be an expert in sedimentary rocks, from your
location. I guess you're attracted to more exotic geography. :)
There's a big tunnel being built here at the moment and my route to work
lets me see most of the constructions. So I've seen plenty of freshly
exposed sandstone lately. Some of the pieces have been beautiful.
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"PM 2Ring" <nomail@nomail> schreef in bericht
news:web.445621421843be3376ba2c900@news.povray.org...
>
> Yes, I was expecting you to be an expert in sedimentary rocks, from your
> location. I guess you're attracted to more exotic geography. :)
Well yes, I do certainly. But that said, the soft rock geology we have here
can be very complex too and poses a lot of challenges. However, the main
problem is that you have to do most work from boreholes, and I miss those
beautiful outcrops sometimes....
>
> There's a big tunnel being built here at the moment and my route to work
> lets me see most of the constructions. So I've seen plenty of freshly
> exposed sandstone lately. Some of the pieces have been beautiful.
>
Oh dear! Temptation! Temptation! :-)
Thomas
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"Thomas de Groot" <t.d### [at] internlnet> wrote:
> "PM 2Ring" <nomail@nomail> schreef in bericht
> news:web.445621421843be3376ba2c900@news.povray.org...
> >
> > Yes, I was expecting you to be an expert in sedimentary rocks, from your
> > location. I guess you're attracted to more exotic geography. :)
>
> Well yes, I do certainly. But that said, the soft rock geology we have here
> can be very complex too and poses a lot of challenges.
Understood. Soft rock is just so much more porous than most hard rocks, and
even if the main particles are not very reactive (like quartz), they
provide plenty of spaces for other molecular species to react with each
other and with whatever is binding the sedimentary rock.
> However, the main
> problem is that you have to do most work from boreholes, and I miss those
> beautiful outcrops sometimes....
> >
> > There's a big tunnel being built here at the moment and my route to work
> > lets me see most of the constructions.
This is a tunnel for motor vehicles, running several kilometres. My
apartment is near one end, my place of work near the other. A collapse
happened (near the middle) in one of the ventillation tunnels late last
year, causing damage to an apartment block. Here's a link:
http://www.industrysearch.com.au/news/viewrecord.asp?id=19863
> > So I've seen plenty of freshly exposed sandstone lately.
> > Some of the pieces have been beautiful.
> Oh dear! Temptation! Temptation! :-)
I've been tempted to grab some samples, before they get crushed and disposed
of... I'd send you some, but the postage would kill me. :)
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"PM 2Ring" <nomail@nomail> schreef in bericht
news:web.4458bb911843be331bd1c060@news.povray.org...
> This is a tunnel for motor vehicles, running several kilometres. My
> apartment is near one end, my place of work near the other. A collapse
> happened (near the middle) in one of the ventillation tunnels late last
> year, causing damage to an apartment block. Here's a link:
> http://www.industrysearch.com.au/news/viewrecord.asp?id=19863
>
Interesting!! Thanks for the info. A familiar problem surfacing here...
>
> I've been tempted to grab some samples, before they get crushed and
disposed
> of... I'd send you some, but the postage would kill me. :)
>
Thank you indeed for your kind thought! But don't! It would be rather
expensive to send useless rocks around the world just for the fun of it. :-)
I have done it for work of course, and also when coming back from holidays I
tend to have a few rocks in my luggage, getting strange looks and frowns
from custom officers....
Thomas
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"Thomas de Groot" <t.d### [at] internlnet> wrote:
> I have done it for work of course, and also when coming back from holidays I
> tend to have a few rocks in my luggage, getting strange looks and frowns
> from custom officers....
>
I brought back a rock from Australia a few years ago. It was a birthday
present and it is striped brown and beige. Its name is Dinkum.
Stephen
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"Thomas de Groot" <t.d### [at] internlnet> wrote:
> "PM 2Ring" <nomail@nomail> schreef in bericht
> news:web.4458bb911843be331bd1c060@news.povray.org...
>
> > A collapse
> > happened (near the middle) in one of the ventillation tunnels late last
> > year, causing damage to an apartment block. Here's a link:
> > http://www.industrysearch.com.au/news/viewrecord.asp?id=19863
> >
> Interesting!! Thanks for the info. A familiar problem surfacing here...
I don't think they've solved the problem yet. They still have a huge machine
near the collapse point which looks like it's still taking vertical core
samples. People should be more careful when building tunnels. I guess it's
hard when you can't really see what you're doing...
> >
> > I've been tempted to grab some samples, before they get crushed and
> disposed of... I'd send you some, but the postage would kill me. :)
> >
> Thank you indeed for your kind thought! But don't! It would be rather
> expensive to send useless rocks around the world just for the fun of it. :-)
:)
> I have done it for work of course, and also when coming back from holidays I
> tend to have a few rocks in my luggage, getting strange looks and frowns
> from custom officers....
That would be fun. Have they ever threatened to break them up to look for
contraband hidden inside? :)
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"Stephen" <mca### [at] hotmailcom> wrote:
> "Thomas de Groot" <t.d### [at] internlnet> wrote:
>
> > I have done it for work of course, and also when coming back from holidays I
> > tend to have a few rocks in my luggage, getting strange looks and frowns
> > from custom officers....
> >
>
> I brought back a rock from Australia a few years ago. It was a birthday
> present and it is striped brown and beige. Its name is Dinkum.
>
>
> Stephen
Strewth, mate! :)
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"PM 2Ring" <nomail@nomail> schreef in bericht
news:web.445b08321843be331bd1c060@news.povray.org...
>
> I don't think they've solved the problem yet. They still have a huge
machine
> near the collapse point which looks like it's still taking vertical core
> samples. People should be more careful when building tunnels. I guess it's
> hard when you can't really see what you're doing...
>
I have the feeling that it was a combination of time and money that led to
the collapse....
> > I have done it for work of course, and also when coming back from
holidays I
> > tend to have a few rocks in my luggage, getting strange looks and frowns
> > from custom officers....
>
> That would be fun. Have they ever threatened to break them up to look for
> contraband hidden inside? :)
>
Well... it is always the question "what is allowed/not allowed for export".
Believe it or not, rocks can give problems, if they are sent in large
quantities (samples for study for instance) and you need special permits.
But for the tourist, there is little to worry about generally, except really
in the case of fossils...
Oh dear! I am afraid we are wandering off into the off topic area.....
Thomas
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"Thomas de Groot" <t.d### [at] internlnet> wrote:
> "PM 2Ring" <nomail@nomail> schreef in bericht
> news:web.445b08321843be331bd1c060@news.povray.org...
> I have the feeling that it was a combination of time and money that led to
> the collapse....
Agreed.
> Well... it is always the question "what is allowed/not allowed for export".
> Believe it or not, rocks can give problems, if they are sent in large
> quantities (samples for study for instance) and you need special permits.
I believe it. We're very fussy about quarantining here.
> But for the tourist, there is little to worry about generally, except really
> in the case of fossils...
>
> Oh dear! I am afraid we are wandering off into the off topic area.....
Yes. Let's get back to raytracing!
Here's a stereo pair I just did of the sandstone block pyramid I posted
earlier. It doesn't look good as a colour anaglyph, unfortunately.
Post a reply to this message
Attachments:
Download 'sandstoneeh0rls.jpg' (172 KB)
Preview of image 'sandstoneeh0rls.jpg'
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"PM 2Ring" <nomail@nomail> schreef in bericht
news:web.445b87391843be331bd1c060@news.povray.org...
> Here's a stereo pair I just did of the sandstone block pyramid I posted
> earlier. It doesn't look good as a colour anaglyph, unfortunately.
>
>
Ah yes, that's nice!
I just thought too that your sandstone texture would be excellent for use
with fossils, like those from the lithographic limestone of Solenhofen in
Germany or those from Liaoning in China... Hmm. Shall think about that
possibility...
Thomas
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