bodleianlibs:In his travels Marco Polo vividly described the cold province of Badakhshan, a prospero
bodleianlibs:In his travels Marco Polo vividly described the cold province of Badakhshan, a prosperous land where horses that descended from Alexander’s horse Bucephalus were once bred and where priceless rubies and the finest lapis lazuli were found.Since ancient times lapis lazuli has been sourced in this remote region, north-east of modern Afghanistan, and exported over vast distances. Its mines on the steep Hindu Kush Mountains, above the Valley of the Kokcha River, can only be reached through a tortuous and dangerous route. Lapis lazuli consists of a large number of minerals, including the blue mineral lazurite, the white mineral calcite and golden specks of iron pyrites.A laborious process transforms this composite mineral into the pigment ultramarine; various grades of ultramarine can be obtained, from the purest extremely expensive deep blue, composed mostly of lazurite particles to the pale grey so-called ultramarine ash.Our conservators recently attended a 2-day workshop learning how to make their own ultramarine pigment for use in our own conservation. See the entire process in our Case Study! -- source link