Roughly 200 to 250 alt. I would bring an atlas as the height makes it easy to just shred a section of a mountain. You will be grabbing residual stuff now but there is normally a good amount on the fringes left over.
Edit: also, Umbris can be in ice so don’t exclude that in your mining.
it’s more like how high…
130-220 is “best” but you can find it as low as 100 while still having 30ish blocks above.
I haven’t had much luck below 190 before. I should probably try again though.
Edit: my experience is only after several hours of the planet spawning. So, it is mostly residual umbris.
I like around 130 myself, but there is a very wide spread.
I’ve found there are large umbris chunks as low as 120-125, also. 300 in about 30 minutes this time around.
As you can tell by the other posts, Umbris has a real good range. If You’re not having luck, go up/down by 10 degrees and you’ll probably find a sweet spot or two.
IMO the range has it’s greatest variance in worlds with prefabs like we have on this planet currently. It really forces the player to move around a bit because there are large holes at the end of some of these rock clusters. At least in the area that I was going crazy in.
This is a great bit of trivia. The last Umbris world we had I had a lot in glacier. Ended up having a few stacks oof that darker red glacier as a result.
thanks guys! You were right, pretty much everything is taken but was able to get a few ores 
Im guessing that there is no mor petrolim right? Im looking in some hotspots that show up on my atlas but cant se any
Edit:
Found it lol
yep, lovely place to visit but no darn way could live there…that’s why I luvs to come home to me home planet, soch I…easy on the eyeballs.
Anyone have coordinates for the gleam? I didn’t get to hoard last time the exo with this colour came around.
Been looking too, but can’t see it!
You might have to randomly throw regen bombs. That is how I normally find gleam.
Edit: Be kind and rewind - throw a regen bomb before you leave.
Yeah, I keep an eye out for suspicious looking holes around. Plenty of times I’ll save a gleam spot and come back and have to toss one, wiped and not regened. But not to be too much of a hypocrite, I’ve certainly been the guilty party too… 
It’s a best effort sort of consideration. I don’t always remember to throw one myself. I have also used up my only regen bomb before and was not able to regen an area.
Sometimes you warp to an exo and forget your atlas… or even worse, your regen bombs.
Too many times a new planet has caused me to forget more than one item.
… Or forget to drop stuff off first and clutter up my inventory even more. Recently posted a shot of a haul on an exo on Twitter and it was pointed out that I had Spanners with me. 
Oops. Not only forgot to drop them off but was totally oblivious to them sitting there the whole time! But yeah, when you first know it is there, it is sometimes quite a mad rush. 
Lol I’ll say so nice find! Thanks
Yay thanks fid
Did find a much better Umbris area yesterday, not totally torn apart yet either. 
