I could be wrong, but here's my initial impression.
The two brooches look a lot like the costume jewelry sold by 1928 Jewelry Company. They made fake vintage looking jewelry.
The Monet necklace is both fake gold and fake pearls.
The "PAT" refers to "patent pending" and was used on Trifari clasps. Like Monet, these would be fake gold and fake pearls.
The pearls in the necklaces are all exactly the same size and shape and have no overtones, so since the clasps are costume jewelry, I'm guessing the pearls are, too.
Now, I could be completely wrong, but from your photos, they look like costume jewelry I owned before I bought the real stuff.
Are there any markings inside the ring? Do you know if it is white gold or silver? It looks like it could be a real akoya pearl.
That said, Monet and Trifari make very nice quality faux jewelry. I have some Richelieu fake pearls from my grandmother from the 1920s or 30s, and wear them for sentimental reasons. So, if you like the pearls and have fond memories of your grandmother, wear them and enjoy them. However, they are only worth about $10-15 dollars if you want to sell them (I did a quick look on Etsy and Ebay). Your best bet would be to offer them to a vintage clothing store.
