Yves Rocher appears to use the same or a very similar base for many of its prestige-line perfumes. In So Elixir, the base appears essentially as the perfume, with patchouli, tonka and musk dominating the composition. In the Secret d'Essences collection, the So Elixir base is more of a background, with other elements being played up instead. Nonetheless, upon an initial spritz of Iris Noir, the fact that it was produced by Yves Rocher becomes immediately evident from the detectable and familiar base. All of this means that if you like So Elixir, then you are very likely to appreciate the rest of the Yves Rocher prestige fragrances. If not, you probably will not.
Iris Noir has a nutty, slightly earthy aspect to it (perhaps due to the ambrette), and the iris appears to be essentially orris root butter, not the flowers of the iris plant. The composition therefore veers toward the dark side, but I feel in this case that because of the musky So Elixir base, a better description than "noir" would be "gris". There is a kind of gray fogginess to the base which does somehow permeate the entire composition.
There also appear to be incense or wood notes in this perfume, which tinge it slightly, with the result that what in So Elixir is foggy musk here really becomes a kind of wet, bluish smoke. This creation definitely seems more oriental than floral to me.
I consider Iris Noir fully unisex, and I like it more in some weather conditions than others. The humidity and temperature appear to affect the expression of the base, making it more musky on some days and less musky on others. But no matter how I may feel about this perfume on even given occasion, I always love the bottle (common to all members of the Secret d'Essences line), and the pursesprays and minis are also very nice!