AusBonsai

Hi everyone
thought I'd show a rock I got today , I'd love to be able to say like fossil finder that I went out bush and found it but I can't . Found it in my local pet shop as a fish tank rock. I really like it and think that when it has a base it'll look pretty good . I'd really appreciate it if someone could tell me what type of rock it is , it looks like 2 types of rock moulded into eachother
peterb

That's a nice rock whatever way it found you pb! Is the lighter stone soft/fragile or hard? I'm not a geologist but I'd say the darker stone looks like ironstone. Is the lighter patterned rock soft or hard/glassy? Aquariums often sell lavarock from NZ but this is totally different and could be from alot of places...maybe Qld??

Whenever you can ask where the rock came from. For some it doesn't matter alot but knowing the provenance is as relevant to serious bonsai/suiseki/rock collectors as it is with antique or fine art collectors IMO. This is a nice find.

Hi F/F , tthanks mate liked it as soon as i saw it , the bottom rock is very hard and the top rock is softer as in you can mark it with something metal. I asked the pet shop guy where it was from but he had no idea .
Peterb

It's very hard to tell what sort of rock it is from a photo, especially for a fine-grained rock. Geologists (and I am one) like to get up close and personal...they don't call us rock-lickers for nothing!!

The rock is either sedimentary comprising an upper layer of siltstone or mudstone and a lower harder layer of more siliceous (lots of silica) material like a chert, or it's volcanic. If it's volcanic then the upper layer is likely a tuff composed mostly of volcanic ash.

Hi JPG, thanks mate , the bottom rock seems to have some quartz veins running through it as well
peterb

Looks a lot like Pelindaba Rock from South Africa.

Hi Craig tried Google pelindaba rock but couldn't get any clear close up pictures

I used to collect these stones for Suiseki when back in South Africa. My dad when I was younger also used them in his fish tanks as well, grew up with them around. Would say over last 10 years or so was becoming harder to find spots to collect, as a lot of the sites have been developed and greed.

Found this picture of a Stone donated by John Naka. I remember seeing a picture of John next to a huge Pelindaba stone when they were out collecting (not sure if the donated stone was from the same trip), was before I joined my previous club in South Africa.
http://scienceviews.com/photo/library/SIA1194.html

Very nice material that pelindaba CraigM. Are they mostly collected for use in terrariums and aquariums? It's a bummer when areas/ecosystems lose there character/integrity due over-collecting. Many fauna species like small amphibians, reptiles etc are heavily impacted by loss of habitat features like rocky outcrops but we have to remember how different circumstances area in these regions impacted by drought/famine/war. Thanks for the link to that information.

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Hi Craig, wow that's a beaut rock. Yes that looks just like the same type of rock, it has the same layers of quartz type rock with the layers of fissured rock . Thanks for providing that link, so now my rock will be called pelindaba rock. How long you been in oz now Craig and did you manage to bring any of your rocks with you . Cheers
Peterb

fossil finder - these rocks were quite heavily used in gardens as well, especially water features. Completely agree re habitat and impact.

peterb - have been in Melbourne for just over 2 years. At the time of moving wasn't sure what I could / couldn't bring into the country, so only brought a couple small ones with. My better stones were left in SA, when my wife returned to SA for a visit asked her to bring some of the smaller stones back, unfortunately my tenant had included them in fill for a new soak pit that was dug... aargh

Have attached couple pics below.

Particularly like that first rock CraigM! Bad luck losing your collection like that but living in Australia will provide plenty of opportunities to build another interesting collection.

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