bottom right and center : cultured akoya
bottom right, natural saltwater
lower strand cultured akoya and natural saltwater (it's a assembly I made, to enhance a bit a very good akoya, adding lenght, and some irregular finish)
higher strand, natural saltwater
top box, natural american freshwater, hammer oyster, spondylus sinensis, cassis cornuta, hippopus hippopus, trisidos semitorla, haliotis iris, pinna-atrina, from source, best bet is atrina vexillum, one has strong red fluorescence, maybe pteria sp(?!), were sold as pteria pearls.
clasps, from left to right, victorian white gold and old mine cut diamonds(one stone is a spinel), french 18K gold with pear and swiss cut diamonds, french platinum with old mine cut diamonds and emerald, unknown white gold with old european cut and rose diamonds, french yellow gold, and french white gold with swiss cut diamonds.
If someone has interest here, I will make pictures of my necklace boxes and share them, to show the design variation; it's very interesting (late XIX to 1950 or so)