I agree with all said above, the pearl used in the design you shared is not from abalone in any form.
There are three types of products from abalone mollusk:
1) natural pearls (rare and very expensive if they are suitable to use in jewelry),
2) abalone mabe pearls (this is what a human can culture with abalone mollusk, the process is quite tedious and not always successful, but since no-one could yet grow a cultured pearl with abalone - abalone mabe pearls are a good and only alternative for today), and
3) cut and polished abalone shell parts used in jewelry (cheap product, but has nothing to do with pearls as such, it's more like souvenir material; one can still make beautiful designs with it).
If you are looking for a pendant with abalone in it - depending on your budget, I would strongly suggest you looking into mabe pearls. They are beautiful and much cheaper than their natural counterparts, more regular in shape (which enables more design opportunities) and if set properly can make a stunning piece of jewelry. Prices per pearl vary depending on the size, but usually you can buy a decent size loose mabe abalone pearl within 150-250 USD.
If that exceeds what you have thought for the project, I would look for honest sellers who use cut abalone shells but who say and price it accordingly in their designs. Once you are done with your search - make sure to share with us your purchase
