The Black Cuillin are mainly composed of basalt and gabbro, the latter being a very rough rock which makes for superb grip for mountaineers. It is from the dark colour of the gabbro that the Black Cuillin receive their name. The summits of the Cuillin are bare rock, jagged in outline and with steep cliffs and deep cut corries and gullies.
The Red Hills
The Red Hills (Am Binnean Dearg in Gaelic) are sometimes known as the Red Cuillin though this is not a local name. They are mainly composed of granitic rock which is paler than the gabbro (with a reddish tinge from some angles in some lights) and has weathered into more rounded hills with vegetation cover to summit level and long scree slopes on their flanks.
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