Lignum nephriticum cup product of narra wood (the namesake with the province) generated opalescent colors when h2o is poured into it. These wooden cups ended up a major pre-colonial and colonial sector of Naga. Naga is the native pre-colonial title of town. It is named following the narra tree https://andersonjxkug.win-blog.com/8025902/5-simple-statements-about-23naga-explained