I live in Paris, and unfortunately, I share your opinion about the Louvre.
The Crowns are displayed in the Apollo's Gallery, along with a few gems and jewels (the 'Côte de Bretagne' spinel, the 'Eagle of Poland' spinel, ruby and enamel brooch).
In the Middle-Ages section of the Museum, you can also see some of the Regalia used at coronations (Charles V's scepter, the 'Hand of Justice', the spurs, etc.).
Several jewels (the ones you have mentioned) are in a display window located at the end of a small corridor near the Napoleon III's Appartments. Unfortunately, some major jewels are not exhibited anymore (Empress Joséphine's pearl earrings, Empress Marie-Louise's emerald necklace and earrings, Queen Marie-Amélie's sapphire and diamond parure, Empress Eugénie 'reliquary' brooch... and the 'Regent', 'Sancy' and 'Hortensia' diamonds!). The jewels exhibited are in a display window with a poor lightning which does not do justice to them. Because of the lightning, the pearls of Empress Eugénie's pearl and diamond tiara have a yellowish glow that I find particularly ugly (I had seen this same tiara a few years ago, when it was displayed in the Apollo's Gallery, and the pearls then looked bright and white!).
Here is the current display:
And here is how the jewels were displayed a few years ago (pictures from Lorenzo's website). You can see the difference!
I did not know that the Bibliothèque Forney had an exemplar of the catalogue of the Russian Crown Jewels. It must have been a thrilling reading! Maybe I should visit it too!