In the 19th century many stone whorls were removed from Sark. More than a dozen cromlechs were broken up to provide boundary stones and farm buildings, and hundreds of small artefacts were dispersed. The whimsical Jersey name rouettes des faitaux associates these 'fairy cartwheels' with the inexplicable landscape of megaliths. Some of the Sark whorls may have had use as weights for drop spindles. This example, found recently at an Iron Age site, is highly polished and decoratively incised, so it was probably worn as a pendant. Green Serpentine is plentiful in Sark; its softness meant the stone could be easily rubbed or drilled. Sark's hard black dolerite was exported as high-quality axes and hammers in Neolithic times. Sark's soft Serpentine encouraged a specialised technology of stone-drilling in the Iron Age.