Improvements to the analytical protocol of lapis lazuli provenance: First study on Myanmar rock samples

The study of lapis lazuli is important to find out information about the provenance of a materialused since the Neolithic Age for the manufacturing of precious carved artefacts. The Badakhshan depositsin Afghanistan are commonly considered as the main source of lapis lazuli in ancient times. However, otherquarries could have possibly been exploited since antiquity. A protocol to distinguish the provenance oflapis lazuli rocks among four known source areas (located in present-day Afghanistan, Tajikistan, Siberiaand Chile) by means of non-invasive techniques was set up in the last years. It is based on differences in thephysical-chemical properties measured in 45 lapis lazuli rocks that constitute our reference database. Theaim of the present paper is to extend the protocol analysing, by means of a multi-analytical approach, 10lapis lazuli rock samples, coming from the quarry district of Mandalay in Myanmar, to find out significantpetrographic and mineralogical markers. Optical microscopy and scanning electron microscopy were usedto perform a detailed petrographic and mineralogical characterisation allowing to distinguish the Myanmarlapis lazuli in three main groups. SEM-EDX analyses on selected mineral phases were performed.