1/f frequency noise in mechanical resonators scales inversely with volume, not with quality factor

Mechanical frequency-shift sensors have never reached their fundamental thermomechanical or quantum limits. Every material, size, and transduction scheme yet examined yields a $1\mathrm{/}f$ floor 1-3 orders higher, with a flicker-noise coefficient $h_{-1}\propto 1\mathrm{/}{V}_{\epsilon }$. Surveying the published record, I find the invariant $h_{-1}{V}_{\epsilon }\equiv {\sigma }_A^2{V}_{\epsilon }\mathrm{/}(2\ln 2)$ independent of device size across 13 decades; volume-independent noise is excluded by 9$\sigma$, site-averaging by 3.8$\sigma$. No $Q$ dependence appears: reported $Q^{-n}$ laws scale equivalently when $Q$ and volume co-vary; only volume scaling survives when they do not. Mass resolution follows as $\mathrm{\mid }\delta m\mathrm{\mid }\propto \sqrt{h_{-1}{V}_{\epsilon }\cdot V}$.