Lignum nephriticum cup made from narra Wooden (the namesake of your province) made opalescent hues when water is poured into it. These wood cups were being a major pre-colonial and colonial sector of Naga. Naga is definitely the native pre-colonial title of town. It's named following the narra tree https://andrevgscn.ampedpages.com/article-under-review-55417790