Pearl Necklace

The clasp reads Made in Japan and US Pat. N...
But don’t know if the pearls are Japanese?

 

Pearls that look like this are termed cerclé. Loads of them are being produced somewhere, don't know if Japan. AJ & some of the others may know.

Edit: Not surprisingly, they seem more commonly to be called circle pearls.

 

Note on the construction: this strand has been made in the simplest possible way; no knots between pearls; ends finished with 2 crimp tubes each with no care to hide them. Unless marked so, doubt clasp is sterling.

 

Those are most likely Chinese freshwater pearls, of no particular age or parentage as I'd generally put it. Only the clasp is Japanese, odds are, and recycled from another necklace. The string looks like a crafter made it.

 

Second that.

 

Just an opinion from what I have learned this far. Look for the knots between .

 

This actually looks as though someone bought a long strand from a bead store/supplier, then just attached an inexpensive clasp by crimping the ends closed. Depending on what was used to string them, may not even have been restrung.