Lignum nephriticum cup crafted from narra wood (the namesake on the province) produced opalescent shades when h2o is poured into it. These wooden cups ended up a major pre-colonial and colonial market of Naga. Naga is the native pre-colonial title of town. It's named once the narra tree (Pterocarpus https://edwinsfrbn.blogzet.com/facts-about-23naga-revealed-42660330