Materials: Raw: Tellurium - Grade 4 - #00021

Tellurium is a rare grade 4 element in Elite Dangerous.

Material traders allow trade with almost every other raw 'element' material. If you wish to trade something in for Technetium, you can do so with other grade 4(5) element material with a ratio of 6:1.

Tellurium is in Category 5, together with Tungsten, Germanium and Nickel.

It is more favorable to use Tungsten as a source for a Tellurium tradxe, this class 3 element material has a 6:1 ratio but it's way easier to harvest than grade 4 or 5 material.
Just keep in mind if you're planning to engineer your ship with blueprints in need of vast amounts of Tungsten, like some Hull reinforcment modifications, it could be better to choose another material for trading in.

Engineers need Tellurium for grade 5 "fast boot" FSD modifications, "weapon enhanced" power distributors and overcharged power plants.

Synthesis uses Tellurium as premium AFM refill and premium SRV Repair material.

Probability of finding Tellurium is about average, regarding its Grade 4 status. AS it is not needed in vast amounts, it's one of the less time consuming materials.

Regular places to find higher quantities of Tellurium are best to be searched for by using, three high content systems for example:

No shortcut available

Known geological hotspots like volcanoes at ice geysers. Use BD+65 210 - Body 7 A - ice geyser. With 'needle crystal' structures you have a high chance of Tellurium.