Here are some photos so others can identify the jewels concerned.
I know most will know what you mean, but perhaps some don't.
What August calls the Empress Marie's sapphire & diamond bandeau.
1. Here worn with the Ladies of India emerald brooch as a centre piece.
2. Here worn with the large sapphire brooch as a centre piece.
3 The earrings
QEII wore them for her wedding
4. The bar brooch