Geology
- Thread starter Tengu
- Start date
That's simple, look underneath if it has a sticker saying made in China then it's Chinese otherwise it's British. Sorry couldn't resist.
That's tough I did geology yeArs ago but the grey Matter is getting to me. Slate is mostly supplied these days from Spain or USA but if you have an old piece from a building in uk then it could be Welsh or English.
If you want some reading this might help.
http://dx.doi.org/10.6028/jres.009.027.
Sent from my iPad using Tapatalk
That's tough I did geology yeArs ago but the grey Matter is getting to me. Slate is mostly supplied these days from Spain or USA but if you have an old piece from a building in uk then it could be Welsh or English.
If you want some reading this might help.
http://dx.doi.org/10.6028/jres.009.027.
Sent from my iPad using Tapatalk
I recall reading that slates from different quarries are different colours, so it would be possible in principle to identify the slate on that basis, but with an old piece then weathering is going to affect that. So I suppose that is no help at all...
How old ? as in how old was the human use of the slate piece in question.
Slate was used by the Egyptians for their 'palettes', while in the UK from Bronze Age at least, we know slate was used for cooking upon. Sometimes slate was used for whetstones, one was found at Verulamium, iirc. apart from roofs and floors.
Why do you want to go to the expense of petrographic analysis anyway ? that's the basis I suspect of your answer. If it's for source then I know it can be done but it needs a background record of slate quarries to compare.
I'd want to know what had been done to the slate. What was it used for ? Were there any evidences of residue for instance….where was it found though ? what context? in all it's ramifications. Work wear analysis perhaps….mind slate can be mde into an ulu type knife by rubbing and polishing it, too.
Very widespread use of slates for roofing is 'relatively' recent. The Romans here mostly used tiles….and the slates they did use were small, and often pointed. It's heavy to transport and it's not always easy to split evenly, tiles came standard sized and were large enough to cover the roofs on purlins without sarking boards beneath.
Slates were sometimes used as floor tiling. If it was local it'd be cheaper than making those fancy tiles, and it contrasted well with other stones that split, like sandstone, colour wise, for designs in 'posh' buildings.
English Heritage has this pdf on stone.
https://archaeologydataservice.ac.u...ch-1416-1/dissemination/pdf/9781848021334.pdf
Best of luck with it
M
Slate was used by the Egyptians for their 'palettes', while in the UK from Bronze Age at least, we know slate was used for cooking upon. Sometimes slate was used for whetstones, one was found at Verulamium, iirc. apart from roofs and floors.
Why do you want to go to the expense of petrographic analysis anyway ? that's the basis I suspect of your answer. If it's for source then I know it can be done but it needs a background record of slate quarries to compare.
I'd want to know what had been done to the slate. What was it used for ? Were there any evidences of residue for instance….where was it found though ? what context? in all it's ramifications. Work wear analysis perhaps….mind slate can be mde into an ulu type knife by rubbing and polishing it, too.
Very widespread use of slates for roofing is 'relatively' recent. The Romans here mostly used tiles….and the slates they did use were small, and often pointed. It's heavy to transport and it's not always easy to split evenly, tiles came standard sized and were large enough to cover the roofs on purlins without sarking boards beneath.
Slates were sometimes used as floor tiling. If it was local it'd be cheaper than making those fancy tiles, and it contrasted well with other stones that split, like sandstone, colour wise, for designs in 'posh' buildings.
English Heritage has this pdf on stone.
https://archaeologydataservice.ac.u...ch-1416-1/dissemination/pdf/9781848021334.pdf
Best of luck with it
M
To some degree its possible even without sending it to the lab.
Welsh slate (sort of purplish colour and cuts well) is different from Burlington (greyish, often with lots of small defects) and they are both different from the greenish slate that comes out of Honister, which if I remember right has the least water absorption out of them.
You can measure the water absorption by weighing them before and after a decent period of immersion, or at least that's one thing we did in Geology at school.
I can't say I'm a fan of Burlington as it doesn't last anything like as well as Honister, it flakes and crumbles away and if replacing a roof (you keep the good slates and re do the battens and felt) you have to get a far higher percentage of new to account for the broken ones.
Obviously there's other types but they were the main ones I had to deal with at the place I used to work at.
Welsh slate (sort of purplish colour and cuts well) is different from Burlington (greyish, often with lots of small defects) and they are both different from the greenish slate that comes out of Honister, which if I remember right has the least water absorption out of them.
You can measure the water absorption by weighing them before and after a decent period of immersion, or at least that's one thing we did in Geology at school.
I can't say I'm a fan of Burlington as it doesn't last anything like as well as Honister, it flakes and crumbles away and if replacing a roof (you keep the good slates and re do the battens and felt) you have to get a far higher percentage of new to account for the broken ones.
Obviously there's other types but they were the main ones I had to deal with at the place I used to work at.
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