No issues with direction, plug it in however it fits. As far as damage goes, crystals are very rugged themselves however the wire leads exiting the crystal package can break off or crack but it would take a real smart impact to do this. Some larger crystals can break free from their holder but these are typically kHz frequency units and your Tx has a frequency in the 72MHz range and that makes the physical size smaller and less susceptible to G-forces from a crash.

The crystal is actually just a thin piece of quartz (a rock !!!) that oscillates(vibrates) at a specific frequency. The thickness of the slice determines the frequency of the crystal. There's actually no real electronic circuitry inside the little silver box with the 2 leads exiting it.

In fact its the same principle that allows us to use a quartz crystal as the sensor inside a modern RC Piezo Gyro.