When you visit a place often enough, you think you have seen all there is to see. For all the photographs of rocks and pebbles that I have taken over the years, I don’t think I had ever noticed so many stones made of iron as I did on my last trip to Rhossili on the Gower Peninsula, South Wales. Mostly they were lying in the narrow strip of pebbles, cobbles, and boulders that is exposed on the upper reaches of the sandy shore, right at the base of Rhossili Down.
Some of these iron stones appear to be made entirely from iron (maybe iron carbonate) while others were sedimentary rock with a solid iron centre, or with groups or bands of small iron nodules. One stone was stratified with black and rust layers. All of them were very heavy and many exhibited concretionary layers. I know very little about these stones. Their forms of iron are distinctly different from the haematite form that I have previously shown in other blog posts about Gower geology, and from the iron pyrites nodules I have featured from Dorset’s Jurassic rocks. Those stones with groups or layers of smaller nodules look like the siderite form of iron that I photographed at Joggins in Nova Scotia. Iron is recorded in Lower Carboniferous rock strata and also in the Coal Measures higher up in the geological sequence, so iron stones on this Gower beach make general sense but they may have been transported there from another location. Clearly more investigation is required.
Jessica's Nature Blog 
Educational as always Jessica – explains some of the colouring I’ve seen in beach pebbles in some locations.
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Thank you. They were amazingly heavy and quite attractive to look at. I will try to find out a bit more about how they are formed and exactly where they came from. Sometimes though I get a bit confused by the terminology used to describe the chemical and physical processes involved.
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What beautiful colours and patterns.
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You’ve definitely got an eye for unusual rocks, Jessica! I love these – and I’ll know what iron looks like now, seeping out of a rock!
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Thank you, Still Walks. I’m glad you like the stones. I tend to see beautiful colours and patterns in unexpected places
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Thank you, Jo. These iron rocks are curious. However, if you are interested in iron really seeping out of rocks, you might want to look at They Breathe Iron: Artistic and Scientific Encounters with an Ancient Life Form, Science&Art Press, 2014, by Linda Grashoff who also writes a WordPress Blog called Romancing Reality.
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Thanks, Jessica!
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Wish I had found this blog before my visit; I really enjoyed your photos. Would you be willing to look at a rock photo from the Gower peninsula for me and try to ID it? It has crystals and composit nuggets.
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I’ll have a go, Linda. You can send the picture to winderjssc@aol.com. It helps with the identification if you can tell me as precisely as possible where you took the photograph.
Happy Christmas.
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