>>64132425
If you've yet to invent metalworking then I suspect you make do with what you have, while some later jade blades we see were likely ceremonial affairs. Dunno if they have any obsidian to speak of in the area as well, though whereas the nephrite is likely a bit behind in hardness there it should be much better in regards to toughness.
All of these ancient jade items are nephrite, the use of jadeite didn't kick off until relatively modern times.
Jadeite cabbage (apparently one of the museums two most famous items, the other one being "the meat shaped stone" which was sadly on loan to elsewhere when I visited).