I first encountered Guerlain Meteorites Perles Light-Diffusing Perfecting Primer during a makeover and was quite taken with its sophistication. It wasn't just the beautiful appearance of the heavy pump bottle with the delicate pearls suspended in clear liquid; the performance of this primer is just as impressive.
I was a bit worried that the light pink cast of the pearls might show up on my skin and clash with my olive undertones, but it doesn't. As you pump out the primer, the pearls get smooshed and mix with the serum-like liquid (without ever contaminating what's left in the bottle. Don't ask me how). The product applies very sheer with a very subtle glow- it's far less obvious than a regular liquid highlighter (Becca, Rouge Bunny Rouge), though until everything sets and dries down you will see the occasional tiny particle.
Speaking of drying- it's highly recommended you give Meteorite Perles a couple of minutes to fully set before applying foundation on top. This primer has a wet consistency at first, though it's not tacky. Once dry, foundations and tinted moisturizers go beautifully smooth over it. The glow is more apparent the thinner your foundation is. I find that compact foundations cover it up completely and you don't see any special effects. However, you can also mix a little of this Guerlain Meteorites Perles with your foundation to add luminosity.
As far as cementing foundation into place, Guerlain Meteorites Perles is adequate but not the longest lasting one on the market. It holds makeup nicely and prevent it from slipping and sliding, but it was not made to keep makeup alive for 12 hours, at least not in the summer. I've experienced fading occasionally, but have noticed that topping my face with Meteorites powder (pearls or pressed, it didn't matter) definitely helps.
Guerlain Meteorites Perles has the familiar Gurelain violet scent. I love it and its classic makeupy feel, but the sensitive of nose or skin should take it into consideration.
Bottom Line: a real luxury.
Guerlain Meteorites Perles Light-Diffusing Perfecting Primer ($69, 1oz) is available from most decent department stores and Sephora, including online.