This leaflet The Stamford Stone Trail has been bought to my attention by one of the Stamford and District Geological Society’s members. I thought you would like to see it , so have put it on the website here for you to read..
p.s. Thank you David.B
The Mysterious Stone :
Firstly I’d Just like to say thank you to Dr Stephen Parry for talking to the SDGS. And to all those who attended our Winter Talk for December. It was another great turn out which was very pleasing to see considering the rather chilli winter evening conditions. For me personally id never realised the importance of this topic. And I would thoroughly recommend you access this link STRATEGIC STONE STUDY for more information.
The bite sized nibbles to eat upon arrival with tea and coffee to drink where welcome treats also.
And i would also like to thank Andrew who bought in what he thought might have been a Meteorite ( pictured above ) and was wandering if anyone present at the talk might have been able to shed some light on one of three of his mysterious stones. Which were found just outside Saffron Waldron in a farmer’s field?
Fortunately I have friend who is an avid collector of Meteorites with many years of experience. I took some photos of Andrews’s stone and sent them with as much information as Andrew could give me on his behalf and with consent. If you’d like to read below this is the response I received and have forwarded the information onto Andrew as requested.
“Two things are for sure. One… it doesn’t have any features (at all) that would indicate it to be meteoritic, and two… it didn’t originally come from anywhere near Essex.
it’s almost certainly part of the Essex post-glacial drift geology and I would suspect it came out of the boulder clay. That’s going to make it tough to identify from the appearance and described properties so far, since the drift geology has rocks that have come from as far away as Scotland and Scandanavia. There are also a great many rocks that have come from North Wales, since the Thames is believed to have been a huge river at one time that originally drained the Welsh Mountains before its headwaters were captured by the Severn River.
There are basalts, quartzites, and sarsens (a type of silicified sandstone) plus all kinds of other erratic’s – including a wide variety of igneous rocks. If the colour rendition in the pictures is accurate then it’s too dark to be a sarsen (they get to pale green but not beyond), and I would assume its rich in chlorite or olivine and of igneous origin. All of the likely candidates will be dense rocks. From the way it has broken it looks like it might be somewhat foliated and there doesn’t seem to be much difference in weathering colour between the broken and unbroken surfaces. On that basis, I would guess it to be a chlorite-rich schist of some kind. Chlorite is a relatively soft mineral, but the rock types it occurs in will not necessarily also be soft.
Although you describe it as weakly magnetised (as opposed to magnetic), that doesn’t narrow it down too much. That will likely be from a secondary mineral, and the only two common possibilities are pyrrhotite and some types of magnetite (the varieties known as lodestone). Either of those might be present in igneous rocks that have green mineralogy. Since pyrrhotite (the mineral itself) is generally only weakly magnetised, there would need to be a lot of it present in the matrix to influence the properties of the rock itself… so I would assume a small amount of secondary magnetite is present. “
Hope to see you at our next Winter Talk: