Hi Drew I have just been scanning through the pearl forum and here is your very lovely pearl brooch! The pearls do look white and lustrous, don't they? They say a good way to tell if you have a good quality pearl is if you can see your reflection in them.
The guru team on Antique Jewelry Investor can only provide opinions unrelated to value. Meantime, please do not hesitate to contact WIW2U Group. They have a valuation service, it's not expensive either. Actually their service has a 100% positive feedback from our visitors.
Enjoy your brooch, yes, there is something special about it!
I love the bow knot brooch. It's so delicate and feminine, and blue and white always are winners in my book.
They could very well be natural freshwater pearls. I love scanning the antique shops in my area (which is near the Mississippi River) for pieces with local pearls and also think I have found some.
It is my personal opinion that items with Natural Pearls will become more and more sought after, hence more valuable, in the days to come, especially as these pieces become scarcer.