Groby Granite

Some days, when the wind was in the right direction, at precisely eleven o'clock, I would hear a siren. It was a weakly thing, not at all urgent, indicating merely a distant danger. Some days I would barely register it, but always aware of what came later: a ground-shaking thud as the local quarry lost another layer of wall.

Groby (pronounced Grooby) granite was a commercial commodity during my childhood. Later I discovered it had another name that made it sound more important to my ears: diorite. It came in green and pink - hard crystals of interlocking feldspar, quartz and mica. When broken into chips it was a useful addition to the metalling of roads,


and the skills of a master-builder could turn it into a beautiful pollution-resistant wall.



Diorite is hard. Its edges never soften. Its origin is in magma which intruded into voids in other rock and cooled slowly allowing the molecules time to order themselves into large interlocking crystals. As a child it was one of my fascinations. After my parents used it to build extensions to their brick-built house I once prowled the village looking for it elsewhere.

I spotted it in the walls of cottages, sometimes partly hidden in rendering



in the walls of shops

and banks



and in the church - at the entrance



and in its tower.


For a project at school I did a survey. The quarry and its rock seemed to me to be a mixed blessing. Surely the regular shaking of the ground would loosen the foundations of houses, I thought, and I was curious if it worried or disturbed people, so I went around with my clipboard, pretending I was cub reporter. But no one seemed to mind and nothing seemed to be damaged. There were no cracks, no subsidence and everyone seemed to view the quarry blasting with equanimity. They shrugged at my questions and seemed bemused that anyone might object. The quarry, after all, came first. It was part of the deal of living here.

I recorded who felt the quarry shake and how hard it seemed to rumble. Did it move pictures? Did it cause people to stop what they were doing and reach out for something to hold? No, it did none of these. They heard it and went on with whatever they were doing. The ground moved slightly but that was expected and controlled and they knew it was nothing to fear. I tried relating the shaking with a geological map - pored over known faults and the many types of rock but there seemed to be little pattern. At the end of my little project I interviewed a geologist and he took me in to see the site. I was overawed by it. The hole in the ground was vast, magnificent and dizzyingly deep. The edge was sharp. Around it the ground was flat and then it suddenly fell away. Whole villages could be contained in it with space to spare. It was something little seen by the public and I felt privileged to be allowed so close. Behind the signs, small buildings and inconspicuous metal gates there lurked, completely unacknowledged, what must have been, I thought, one of the wonders of the world.

It is closed now, the supply of diorite exhausted or not required - I am not sure which. There are no sirens or blasts and it seems to me that Groby has lost a little of its character. There are other industries now - the smaller cleaner industries of the twenty-first century - making valves and specialised pieces of engineering. But every time I pass the old signs for the quarry I think of that chasm in the ground and wonder if it is still there.