If this is what I think it is, it is cotton. I've seen a lot of the Blue Heron stuff in person (it's beautiful), and definitely know they do a laceweight cotton like that. I haven't seen a wool lace like that, but maybe.
Thanks everyone - think I'm going to send them an email and check, everywhere else on the net lists it as cotton, it seems - and then get some (argh, the money!). I really need a high-paying knit-what-I-want job.