Very interesting. I also had always assumed that "jade" simply meant "green" or "lightly oxidized" (and maybe it really does for the bulk of US distributors since the term seems more common to the rather pedestrian offerings of US mega-distributors who don't specialize in anything.)
On the other hand, Guang at Hou De certainly knows of what he speaks. It might be worthwhile to e-mail an Upton or SpecialTeas and ask what they mean by "jade" in the name of their Formosa oolongs. Perhaps they really are informing us of the cultivar (but not the the harvest year?!).
Guang as quoted by hop_goblin wrote:Si Cha are mostly used for tea oil production
And that brings us full circle to the Long Jing question, the answer to which I still await from Daniel at TeaSpring via the Oracle of Chip.
Chip, did you ever contact Daniel about oils used in processing Chinese greens? If you did not, give me the green (jade) light and I will email him.