Pearls on cameo frame. Real? What type?

[stevepalm]

Hello Folks,
I purchased a cameo with 4 pearls in the frame.
They are a little gritty but not as gritty as the chinese fresh water pearls I posted yesterday, whatever that means.
The left, right and bottom pearls look same vintage and are different shapes.
The top pearl (1st pearl picture) is round and may be a replacement, although the color pretty much matches with my novice eye.
The cameo and frame are at least 100 years old.
The frame is probably pinchbeck and got gold.
I would like to know if the pearls are real and origin would be very helpful.
Thank you very much and any help is greatly appreciated.

[Caitlin]

The three lower pearls look original. I am not sure about the top pearl. It looks like a replacement and a cultured one at that. The luster is completely different on that one and it is almost perfectly round.