From Wikipedia: "The concentration of active psilocybin mushroom compounds varies not only from species to species, but also from mushroom to mushroom inside a given species, subspecies or variety. The same holds true even for different parts of the same mushroom. In the species Psilocybe samuiensis, the dried cap of the mushroom contains the most psilocybin at about 0.23%–0.90%. The mycelium contains about 0.24%–0.32%."

So for 3.5g ≈ [8.05mg ; 31.5mg] And for 2.5g ≈ [5.75mg ; 22.5mg]