Lignum nephriticum cup manufactured from narra wood (the namesake with the province) developed opalescent hues when water is poured into it. These picket cups had been A serious pre-colonial and colonial industry of Naga. Naga would be the native pre-colonial title of town. It's named following the narra tree https://trentondseqb.theblogfairy.com/27807322/the-2-minute-rule-for-23naga