Letium Bio Samples is a Mission Item used in the 
Korolev Campaign Mission Research Costs Part 5.
The Mission requires the Prospector to visit the Waterfall Labs on Bright Sands and collect 5 Letium Bio Samples items.
There are 8 Letium Bio Samples within Waterfall Labs. They look like Sample Containers filled with a purple good. The Prospector only needs to collect 5 out of the 8 to be able to progress in the mission. See their locations on the Interactive Map, as well as on the image below.
Description
A container preserving... something. A label on the side states: WARNING: HIGH LETIUM CONTENT, DO NOT SHAKE
Story
In Research Costs Korolev is researching how to use 
Letium for easy exploitation of the material. They recruited an 
Osiris scientist off the books to help them with this research. According to the scientist, Osiris was researching the presence of Letium within creatures. The Prospector is send to Waterfall Labs to bring back any samples that Osiris was studying. In Research Costs Part 7, Korolev has been able to extract stable Letium from the Letium Bio Samples. After Research Costs Part 9, and the continuation of the project in Heavy Construction, it is suggested that the research was successful and that Korolev was able to stabilize Letium.
Gallery
