ct on ▁Hill ▁( see ▁picture ) ▁made ▁from ▁Ash ford ▁Black ▁Mar ble ▁and ▁other ▁min er als . ▁ ▁William ▁Martin , ▁who ▁at ▁one ▁time ▁worked ▁with ▁Watson , ▁wrote ▁the ▁first ▁scientific ▁study ▁of ▁foss ils . ▁His ▁Pet r ifact a ▁Der bi ens ia ▁ ▁rec ount s ▁that ▁White ▁Watson ' s ▁uncle ▁and ▁workers ▁at ▁the ▁Black ▁Mar ble ▁quar ry ▁called ▁some ▁of ▁the ▁foss ils ▁" c roc od ile ▁t ails " ▁as ▁they ▁thought ▁they ▁were ▁the ▁remains ▁of ▁cro cod iles . ▁ ▁The ▁craft ▁of ▁in lay ing ▁black ▁mar ble ▁was ▁res umed ▁in ▁the ▁ 1 9 9 0 s ▁by ▁Don ▁Edwards , ▁who ▁ran ▁a ▁rock ▁and ▁min eral ▁deal ership ▁in ▁the ▁Derby shire ▁village ▁of ▁T ides well . ▁In ▁ 2 0 0 6 ▁it ▁was ▁announced ▁that ▁Bu xt on ▁Museum ▁had ▁purchased ▁the ▁Black ▁Mar ble ▁collection ▁that ▁had ▁been ▁left ▁by ▁John ▁Michael ▁Tom lin son . ▁He ▁had ▁spent ▁over ▁ 5 0 ▁years ▁putting ▁together ▁the ▁collection ▁after ▁finding ▁that ▁his ▁ancest ors ▁had ▁been ▁involved ▁in ▁Ash ford ▁Black ▁Mar ble ▁manufact uring . ▁Derby ▁Museum ▁has ▁a ▁diagram ▁of ▁E ct on ▁Hill ▁made ▁from ▁Ash ford ▁Black ▁Mar ble ▁and ▁other ▁min er als . ▁ ▁See ▁also ▁ ▁List ▁of ▁types ▁of ▁lim estone ▁List ▁of ▁types ▁of ▁mar ble ▁No ir ▁Bel ge ▁ ▁References ▁ ▁S ources ▁ ▁Derby shire ▁Black