The Royal Order of Splendor is dishing about Sofia's tiara:http://orderofsplendor.blogspot.com/
All they got on the tiara is that's it's designed in the Art Deco style and it's a gift from CG & Silvia. They're not sure if it's an estate piece or brand new; and that gives me pause. Art Deco style can be replicated, from the cheapest costume jewelry line to a skilled jeweler. Since Art Deco got its start in the 1920's it can give a piece of jewelry a sense of history.
Here's an art deco inspired tiara that's fake:
Yes it's looks beauty pageant.
Even if the tiara has real stones Sofia was short changed because her tiara doesn't break into multiple pieces. Here's Sofia's tiara:
Here's Stephanie of Luxemburg's tiara, a wedding gift from her parents:
Here's an Art Deco tiara:
And I bet if Sofia knew she was getting an emerald and diamond tiara as a wedding gift, she would have opted for these:
Dollar bet Sofia has her wedding tiara appraised.