The stone had been washed out of a drumlin made by glaciers as they retreated at the end of the last ice age.
It was a pretty pink colour with sparkles as you can see from the pictures below.
I simplified the stripes a bit and then decided to weave sideways. I had chosen just 4 colours but would be able to blend more by combining the weft in different ratios.
The weaving is finished and I have mounted it on a canvas.