Complex sentence: The primary feature of Loch of Butterstone, is the clearness of the water, which has been described as "gin" clear, which is particularly noticeable in Scotland, when most lochs are peat lochs, and are therefore peaty in colour.
Split into simpler sentences: The primary feature of Loch of Butterstone, is the clearness of the water, which has been described as "gin" clear. This startling clearness is particularly noticeable in Scotland, when most lochs are peat lochs, and are therefore peaty in colour.