Flux Crystal (Thaumcraft 6)

The Flux Crystal is a glowing ore added by Thaumcraft 6. It is found in clusters of 1-64. When mined, it will drop 1-4 Vitium Vis Crystals (the number of crystals it drops is determined by looking at the block). It is unaffected by Silk Touch.

Flux Crystals will grow with enough Flux. However, they cannot be farmed without the Crystal Farmer Research.

Put your crucible under or near any of the six base crystals that grow in caves and overflow crucible. Crystals in the same chunk will turn slowly in to flux crystals which drop 1 - 4 Vitium Vis crystals (1 x Vitium).

Crystal Farmer Research
"Crystal Farmer" is a Research added by Thaumcraft 6. With it, Vitium Vis Crystals can be used to make Flux Crystals in an Infusion Altar, as seen below.