John Faithfull 🌍πŸ‡ͺπŸ‡ΊπŸ΄σ §σ ’σ ³σ £σ ΄σ ΏπŸ§‘βœŠπŸ»βœŠπŸΏOct 21, 2024

How did I not know this??? 🀯 πŸ€“ Most ordinary porcelain is basically mullite and glass. 😊 Mullite - first found in nature in samples from Mull, and named by Norman Bowen, and co-workers, in 1924. Although rare in nature, it is a ubiquitous material in industrial and other ceramics. #Mull #Mullite #Mineralogy #Geology #Porcelain #ceramics

PS pdf of Bowen et al's paper available on the superb rruff website: https://rruff.info/uploads/JWAS14_183.pdf

Show threadPeter L Bowden
@FaithfullJohn
I believe Mullite is a constituent mineral in Porcellanite - I posted this on Twitter a couple of years ago:-
"Saw a programme about polished axe heads, made from porcellanite, found in 2 localities in Co. Antrim. The variety of porcellanite is a hornfelsed lateritic soil, between Palaeogene basalt lavas.
Have you ever come across this rock type in Scotland, e.g. Skye or
@geologymull"
Oct 22, 2024 at 10:42amWeb
Show threadJohn Faithfull 🌍πŸ‡ͺπŸ‡ΊπŸ΄σ §σ ’σ ³σ £σ ΄σ ΏπŸ§‘βœŠπŸ»βœŠπŸΏOct 22, 2024
@PeterLBowden1 @geologymull I've seen that too. There is VG porcellainite near Staffin in Skye (it was used by local Mesilothic-Neolithic folk). It looks a wee bit like the Mull mullite buchites. I need to XRD some porcellainites! πŸ€“
Show threadBob McIntoshOct 26, 2024
@FaithfullJohn @PeterLBowden1 @geologymull
The only reference in the 1966 N Skye memoir is this: "Lower 'Ostrea' Beds. It consists of angular fragments of dark limestone originally a layer built up by the confluent growths of the alga Cayeuxia nodosa Anderson, but penecontemporaneously brecciated and re-cemented. The algal nodules are grey-blue in colour with a porcellaneous texture, and weather creamy white."
Would it be this?
Show threadJohn Faithfull 🌍πŸ‡ͺπŸ‡ΊπŸ΄σ §σ ’σ ³σ £σ ΄σ ΏπŸ§‘βœŠπŸ»βœŠπŸΏOct 26, 2024
@scotfot @PeterLBowden1 @geologymull not sure - the exposures I saw had been created during the new road down to the pier. Very abundant pink porcellainite on/above road cutting cliff. Wasn't "official" fieldwork so no field notes or grid ref, and it was at least 23 years ago 😱😁 !
Show threadBob McIntoshOct 26, 2024
@FaithfullJohn @PeterLBowden1 @geologymull
Always wise to leave something undone! btw on GeoGuide we are adding a layer for links to BGS 6" maps. Links are not operational yet from the webGIS. Text links are from this page https://geoguide.scottishgeologytrust.org/p/bgs/mullmemoir/bgs_mull_46 (yes - we are starting with Mull and work in progress!πŸ˜€
BGS maps for Mull | GeoGuide

Show threadJohn Faithfull 🌍πŸ‡ͺπŸ‡ΊπŸ΄σ §σ ’σ ³σ £σ ΄σ ΏπŸ§‘βœŠπŸ»βœŠπŸΏOct 26, 2024
@scotfot @PeterLBowden1 @geologymull superb! 🀩πŸ₯°πŸ‘ BGS is so good at getting digitisation done to make open tools, rather than just talking about it... #BGS #BritishGeologicalSurvey #OpenScience
Show threadBob McIntoshOct 26, 2024
@FaithfullJohn @PeterLBowden1 @geologymull Yes, BGS make the content available (including sheet outlines!) largely under OGL and users such as Scottish Geology Trust can innovate access with apps like GeoGuide. Seems to work well! Access to Field slips would be nice in the future!