Outward

For this you need to find all 9 special sample types. When you turn in an unidentified ore, molepig or plant from the Caldera region to Evangeline Vallier in New Sirocco, you have an equal chance of 6 rewards (different for each type). 3 of them in each set are these special sample types. The wikipedia has a page and some maps for it. The page isn't perfect and seems to have some minor errors but will work more than well enough for this : https://outward.fandom.com/wiki/Unidentified_Samples

Basically, the samples work on 4 different rotations. Supposedly they change every 2 days but at least in the old version (not Definitive Edition) I could only get the rotation to change by doing a full area reset (AKA skipping 7 days by doing construction tasks in New Sirocco or sleeping). I slept for probably 2-3 weeks and never saw the rotation change.

If you look at the map for rotation A, you'll see letters with numbers, M is molepig, P is plant, O is ore sample. The important thing to remember is that each one is a POSSIBLE spot where a sample could be, and that each letter/number combination only spawns once per rotation. So once you find the O2 ore sample, don't bother checking the other O2 spots, they will be empty. Same for O1, M5 etc. Only one from each set spawns per rotation. The good news is that the spawns are set per rotation, so once you find O2 for rotation A, every time rotation A comes up O2 will be in the same spot, though it will be empty until you area reset. So once you've got a list of the spawns you can collect a bunch of samples pretty quickly, which is probably when you'll be close to having what you need and it doesn't matter anymore

Anyway, note that you need all 9 special sample types in your inventory at the same time. I had them all in the New Sirocco stash and the achievement didn't pop until I took them all out.

Molepig

Ectoplasm
Digested Mana Stone
Petrified Organs

Ore

Diamond Dust
Chromium Shards
Amethyst Geode

Plant

Flash Moss
Bloodroot
Voltaic Vines