Lewisian Gneiss – Recumbent
Jonathan >
Lewisian Gneiss is mostly derived from granite which, having been subjected to high pressures and temperatures deep in the Earth’s crust, has been metamorphosed into something like this –
A giant recumbent boulder of weathered Lewisian Gneiss. It’s such a hard, unforgiving rock that it will have taken 400 million years for the weather and other natural processes to etch the character into this boulder.
An interesting texture!
J > Lewisian Gneiss can be variable – according to the conditions that created it ; but mostly it has a surface that is glassy and incredibly resistant to, well, anything and everything. This boulder showed no evidence of being crumbly, flaky, and I couldn’t make the slightest impression on it trying to scratch it with another stone. So it must have taken millions of years to achieve this ‘texture’ (which was in a sense exaggerated thanks to the angle of the sunlight).
Yep, that looks like the stuff that we have too…..☺️