The Davis Square Community

My four year old really wants to see some Alexandrite. (It's a cool gem, a variant of chrysoberyl that changes color.) We've checked the Museum of Science and the Harvard Museum of Natural History  (though, to be fair, we've been unable to find anyone who works in the applicable departments at HMNH to make sure we haven't missed it in their huge collection). We've also called the reference librarians at Tufts, Somerville, and BPL and been unable to get an answer. 

I was wondering if your collective wisdom could help a tired mom out? I'm not dedicated to a museum -- if there's a weird gemologist who is willing to let a four year old gawk at an incredibly rare and expensive gem without hope of purchase, we'd take that (and be willing to bribe, I mean compensate him or her with cookies....)

Thanks.