Registered Buildings

[John Wright]

On 8/1/2023 at 10:37 AM, Barlow said:

  

 

Pooilvaaish stone is not soft (in stone terms). In the vernacular "it's as hard as fuck" sort of thing. So is Castle Rushen limestone of course, and that's not soft either. (Whereas Peel sandstone is soft).

Marble is less porous than limestone and as such is considered to be more durable than limetone. Both from the same make-up of calcite. Generally, Pooilvaaish limestone has not gone through the full metamorphosis of pressure and temperature to be considered as a true marble.

So Pooil Vaaish/Pooilvaaish stone is somewhere in between limestone and marble. And certainly not soft although it may well have other qualities that might not be 100% ideal for steps.

Certainly 20 years ago there are at least some steps, or parts of steps, at St Paul's Cathedral that could well be Pooil Vaaish. 

 

 

The problem with pooilvaish marble is that it is soft, in the sense that water gets in, and weakens the structure, especially when the water freezes, and it flakes and bits fall off.

[John Wright]

On 8/2/2023 at 11:22 AM, Gladys said:

You are right, I think it was Carlo rather than Carlos.

 

I hated Carlo with a vengeance. The food was mediocre at best. And I don’t want an over familiar loud Italian standing at the end of my table swearing whilst I eat. Thank you.

[TheTeapot]

13 minutes ago, John Wright said:

The problem with pooilvaish marble is that it is soft, in the sense that water gets in, and weakens the structure, especially when the water freezes, and it flakes and bits fall off.

Are you talking about the dark limestone that comes out of that (occasionally) active quarry? Cos if so, you're talking nonsense. That's quality stone.

Edited August 15, 2023 by TheTeapot

[John Wright]

12 minutes ago, TheTeapot said:

Are you talking about the dark limestone that comes out of that (occasionally) active quarry? Cos if so, you're talking nonsense. That's quality stone.

Yes. And it has poor weathering qualities when exposed to rain and cold. Great for internal use. Not so good for external. 

[TheTeapot]

Just now, John Wright said:

Yes. And it has poor weathering qualities when exposed to rain and cold. Great for internal use. Not so good for external. 

I build external walls with it.

[TheTeapot]

Like, I go down to the quarry and pick stone. Use their awesome press to break it too, that's a cool thing. It is great stone for building with, good edges, good corners. Will last for hundreds of years in a wall. I have no idea what you're on about.

[Mercenary]

23 minutes ago, TheTeapot said:

Like, I go down to the quarry and pick stone. Use their awesome press to break it too, that's a cool thing. It is great stone for building with, good edges, good corners. Will last for hundreds of years in a wall. I have no idea what you're on about.

It does weather though, compared to a granite 

[TheTeapot]

8 minutes ago, Mercenary said:

It does weather though, compared to a granite 

The stuff out of stoney mountain is a form of granite, and its often shit. 

[The Phantom]

11 hours ago, TheTeapot said:

The stuff out of stoney mountain is a form of granite, and its often shit. 

 

11 hours ago, Mercenary said:

It does weather though, compared to a granite 

Granite will weather.  Dilute acid in rain and sea water reacts with the Feldspar present in a reaction known as hydrolysis. 

The volcanic rocks down at Scarlett are Basalt, which is essentially the same chemical composition as granite, but has cooled faster so has smaller crystals. 

There are actually examples of this down at Scarlett.  There is a basaltic dyke intruding into the limestone which has been weathered out faster than the limestone and forms a trench pointing out to sea. 

[The Phantom]

12 hours ago, John Wright said:

The problem with pooilvaish marble is that it is soft, in the sense that water gets in, and weakens the structure, especially when the water freezes, and it flakes and bits fall off.

Marble does not have any layers and it is not porous, the water does not 'get in'.  Similar to granite, what happens is dilute acid in rain (made even more so prevelant by the famous 80s 'acid rain') reacts with the calcium carbonate in the marble that forms the matrix holding it together.  This only really happens on the surface though and results in a sugary texture.

Limestone once metamorphosed creates marble.  Same chemical construction.  An easy geologist test for determining this is some drops of hydrochloric acid will fizz reacting with the calcium carbonate.  A sped up version of this rain weathering. 

[John Wright]

12 minutes ago, The Phantom said:

Marble does not have any layers and it is not porous, the water does not 'get in'.  Similar to granite, what happens is dilute acid in rain (made even more so prevelant by the famous 80s 'acid rain') reacts with the calcium carbonate in the marble that forms the matrix holding it together.  This only really happens on the surface though and results in a sugary texture.

Limestone once metamorphosed creates marble.  Same chemical construction.  An easy geologist test for determining this is some drops of hydrochloric acid will fizz reacting with the calcium carbonate.  A sped up version of this rain weathering. 

Pooilvaish “Marble” isn’t marble. It isn’t exactly limestone either. It’s a fine rock laid down in the sea with thin layers or banding in lots of the beds. It has been exposed to heat but not enough to convert to marble. 

[Gladys]

You boys getting your rocks off!

[The Phantom]

5 minutes ago, John Wright said:

Pooilvaish “Marble” isn’t marble. It isn’t exactly limestone either. It’s a fine rock laid down in the sea with thin layers or banding in lots of the beds. It has been exposed to heat but not enough to convert to marble. 

FFS why call it Marble then?  To be honest I've never actually taken a close look at it with a geological eye.  Looking at their website they claim it's black limestone. 

I met an Ozzie guy on the plane a few years ago who was coming to pitch some work at the quarry.  He was an expert in splitting the rock using water or some sort of slurry, instead of the splitting wedges they currently use.  It was an interesting chat. 

[John Wright]

8 minutes ago, The Phantom said:

FFS why call it Marble then?  To be honest I've never actually taken a close look at it with a geological eye.  Looking at their website they claim it's black limestone. 

I met an Ozzie guy on the plane a few years ago who was coming to pitch some work at the quarry.  He was an expert in splitting the rock using water or some sort of slurry, instead of the splitting wedges they currently use.  It was an interesting chat. 

It’s historically been called marble. There was a trade descriptions complaint in the 80’s and they switched to limestone

[Barlow]

13 hours ago, John Wright said:

The problem with pooilvaish marble is that it is soft, in the sense that water gets in, and weakens the structure, especially when the water freezes, and it flakes and bits fall off.

 

There are effectively many different grades of Pooil Vaaish, depending on which layer it has been extracted from. And apparently there is a layer, way down yonder, that is white. This was found in a bore that was carried out by a University in the 1950s/60s.

For outdoor work the stone has to be carefully selected and laid. Therein lies the skill, knowledge and experience. Every single piece of stone is different and has different qualities.

4 minutes ago, The Phantom said:

FFS why call it Marble then?  To be honest I've never actually taken a close look at it with a geological eye.  Looking at their website they claim it's black limestone. 

I met an Ozzie guy on the plane a few years ago who was coming to pitch some work at the quarry.  He was an expert in splitting the rock using water or some sort of slurry, instead of the splitting wedges they currently use.  It was an interesting chat. 

Most of the stone can be polished and so legitimately can be classed as a marble rather than a limestone.

Water is a well used method for splitting impervious/semi impervious  strata marble such as at Pooil Vaaish.