Oooh oooh oooh... this one is easy for me! I hope I can help.
Plan A: My philosophy is if I don't wear something, I will sell it, no matter how rare or hard-to-find the piece is. I know, sell turquoise?! Big Akoya is speaking heresy! But stay with me please.

If I am not using something, it's a total waste. Plus, by keeping things, it creates a false economy. It looks like there is all this bling to wear, but it's not true as there are pieces that are just never worn. I prefer to free up that space and buy bling I will wear. I don't wear 10 motifs or pendants either. For me, they are very hard to wear as my tops are mainly scoop necks/ballet necks. I think 10 motifs and pendants look best on an open neck, Vneck, or collared blouse. I prefer longer necklaces; that's just me. That said, if I had those pieces, I would sell them. Turquoise is in demand now; but trends change, and turquoise may not be in such demand in the future. Part of the allure & demand of VCA turquoise is its rarity and that you can longer get the piece. Turquoise itself is not a very popular stone as it can be hard to match with clothing. There was a time when amethyst was THE stone. It was rare, but then another source was found in Brazil, and the price & allure of amethyst crashed. The more likely scenario is VCA will find another turquoise mine (it's bound to happen), and if VCA produces turquoise again, the resell value of turquoise pieces will crash from what it is today. I would strike while the iron is hot and sell! You will make great money from your sale. I would then take those funds and get a 16 motif! No doubt in my mind that is what I would do!


I love turquoise, and if VCA were to offer me a WG turquoise 10 motif now at store retail price of only say, $8K, I would turn it down as I simply do not wear 10 motifs. To keep a piece because it is rare or a high-demand piece is not a good reason for me.
Plan B: If mentally you can't part with your pieces... on your turquoise, you could attempt to make a long necklace. You could string your turquoise 10 motif and 5 motif together to make a 24". However, now you have the dreaded second clasp showing.

What to do? A very wise person showed me how to use animal clips to hide the clasps!

You now have two clasps, so what I would do is position one clasp near the back of your neck. For the second clasp, I would add an animal clip to cover it (like I do my panda swinging on the side of my 20 motif). Hmm... what clip would I buy to make it pop? I like the dove or the dog to go with turquoise. The downside to this is 24" is not very long. Depending on your torso and how boobie you are, it may land in no-man's land and not be a great look. Meaning... it may land on top of your boobies (ugh), or it may land slightly past your boobies and make the chain look like it's falling off a cliff (double ugh). Play with it and see how it looks.
On the 16 motif... I love the 16 motif! I tried it on last time I was at NYC. I tried it on to look at WG with GMOP as I wanted to see how a WG GMOP combo would look for a 20 motif. Well, I am now in love with the 16 motif. It's so light and airy and those mixed motifs look great and pop. I'm not sure which 16 motif combo you are considering, but that 16 motif is so beautiful to me. And it's so 1920s flapper! It's the 2020s... let the long necklaces swing!
I hope that was helpful to give you some ideas.