▁p iet ra ▁dur a . ▁ ▁History ▁ ▁The ▁min eral ▁has ▁been ▁used ▁decor atively ▁since ▁pre histor ic ▁times ; ▁the ▁first ▁recorded ▁customer ▁was ▁B ess ▁of ▁Hard wick ▁in ▁ 1 5 8 0 . ▁ ▁Henry ▁Watson , ▁the ▁uncle ▁of ▁Derby shire ▁ge ologist ▁White ▁Watson , ▁is ▁regarded ▁as ▁one ▁of ▁the ▁key ▁figures ▁in ▁the ▁development ▁of ▁the ▁local ▁industry ▁of ▁in lay ing ▁Ash ford ▁Black ▁Mar ble ▁in ▁the ▁ 1 7 5 0 s . ▁He ▁owned ▁a ▁water - power ed ▁mill ▁at ▁Ash ford ▁in ▁the ▁Water . ▁ ▁There ▁was ▁a ▁th riv ing ▁trade ▁in ▁the ▁manufact ure ▁of ▁ur ns , ▁ob el is ks ▁and ▁other ▁decor ative ▁items ▁from ▁Ash ford ▁Black ▁Mar ble ▁during ▁the ▁late ▁ 1 8 th ▁and ▁early ▁ 1 9 th ▁century . ▁John ▁Ma we ▁had ▁a ▁museum ▁in ▁Mat lock ▁Bath ▁that ▁de alt ▁in ▁black ▁mar ble ▁and ▁Ann ▁Ray ner ▁eng ra ved ▁pictures , ▁next ▁door ▁at ▁another ▁museum , ▁on ▁black ▁mar ble ▁using ▁a ▁diam ond . ▁Many ▁fine ▁examples ▁of ▁eng ra ved ▁and ▁in la id ▁black ▁mar ble ▁exist ▁in ▁local ▁collections , ▁including ▁those ▁of ▁Derby ▁Museum , ▁Bu xt on ▁Museum , ▁and ▁Ch ats worth ▁House . ▁In ▁ 2 0 0 9 ▁huge ▁blocks ▁of ▁un work ed ▁Ash ford ▁Black ▁Mar ble ▁were ▁un ear th ed ▁during ▁exc av ation ▁work ▁near