STEPPING STONES YOUR GUIDE TO BEACH FINDS

Whitby jet

Midnight black, with a brilliant lustre (right). A close relative of coal, derived from decaying wood and found in Whitby, North Yorks.

Banded agate

A type of quartz with roughly concentric coloured curves which, when polished and stained, produces beautiful, lurid colours.

Flint

Grey flint often acquires a thick white coating on the beach. Made of solid silica, originally found in a mass of chalk. A sedimentary rock, formed by

sediments laid down in the sea.

Serpentine

Red (left) or green (right), igneous rock – formed by intense heat after molten material has solidified. Abundant in the Lizard headland, Cornwall.

Marble

A metamorphic rock, meaning one that has changed its nature. Marble is metamorphosed limestone, where the calcium carbonate of the limestone has been recrystallised into a lovely looking – and lovely feeling – mosaic pattern.

Amethyst

A type of quartz with a light purple or violet colour. Once cut and polished, they are a delight. Found in Cornwall and the east coast of Scotland.