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.

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.

Recipe
They can be also acquired by placing an overflowing Crucible near (but not above) the six primal aspect crystals.