I saw a lichen I've never seen before on some lava outcroppings--and wondered whether anyone here could steer me in the right direction to find its name.

It grew skin tight against the basalt;
it was the most incredible deep chartreuse color with a metallic cast--I thought of it as chartreuse gold;
the colony was probably very old in that you would have had to have had a very sharp knife to scrape it from the basalt;
running your fingers across its surface, you would have felt a very tightly compressed, pimpled feeling--almost like sandpaper that's been sanded down past any practical use--fine-grained, used, smoothed-down sandpaper.

But, wow! The color! The way that lichen shone in the sunlight! Chartreuse metallica! Loveliest natural growing (glowing) thing I've seen in a long while.

Was it really lichen? Probably--and probably old colonies of it would be my guess.

Thanks for any input here. I've been online all night trying to find it, but no go yet. I hope it has a beautiful name whenever it pops up.

Best regards,
WildsWanderer