Chockstone Forum

      Sponsored By
      ROCK
   HARDWARE

Chockstone Photography

Australian Landscape Prints

Chockstone Forum - General Discussion

General Climbing Discussion

Topic Date User

buying boulders 24-Jun-2013 At 12:44:17 PM Snappy

Message

On 24/06/2013 One Day Hero wrote:
>On 24/06/2013 Snappy wrote:
>>My assumption (which you can feel free to
>>disregard, or google, if you want) is that extrusive rock such as rhyolite
>>would have a higher porosity than intrusive rock such as granite.
>
>Not the case with Canberra Rhyolite.

Yep, turns out rhyolite has quite a range (including less porous than granite).

On 24/06/2013 Snappy wrote:
>Seeing as I am interested now:
>http://lmrwww.epfl.ch/en/ensei/Rock_Mechanics/ENS_080312_EN_JZ_Notes_Chapter_4.pdf
>Page 2.
>
>Granite: Dry density: 2.53 – 2.62 Porosity:1.02 – 2.87%
>Rhyolite: Dry density:2.40 – 2.60 Porosity:0.40 – 4.00%
>Sandstone: Dry density: 1.91 – 2.58 Porosity:1.62 – 26.4%
>

I am guessing that the Canberra rhyolite you are talking about falls closer to the 0.4% than the 4% then.