Crystals over 30 MHz (as much as >200 MHz) are usually operated at series resonance exactly where the impedance appears at its minimum and equal to the collection resistance. For these crystals the collection resistance is specified ( Large-frequency crystals are usually Reduce in the shape of a simple rectangle https://bookmarkspecial.com/story19161951/the-fact-about-smd-crystal-oscillators-that-no-one-is-suggesting