  Monolayer jacutingaite (Pt$_2$HgSe$_3$) has been recently identified as a
candidate quantum spin Hall system with a 0.5 eV band gap, but no transport
measurements have been performed so far on this material, neither in monolayer
nor in the bulk. By using a dedicated high-pressure technique, we grow crystals
enabling the exfoliation of 50-100 nm thick layers and the realization of
devices for controlled transport experiments. Magnetoresistance measurements
indicate that jacutingaite is a semimetal, exhibiting Shubnikov-de Haas (SdH)
resistance oscillations with a multi-frequency spectrum. We adapt the
Lifshitz-Kosevich formula to analyze quantitatively the SdH resistance
oscillations in the presence of multiple frequencies, and find that the
experimental observations are overall reproduced well by band structure
ab-initio calculations for bulk jacutingaite. Together with the relatively high
electron mobility extracted from the experiments ($\approx 2000$ cm$^2$/Vs,
comparable to what is observed in WTe$_2$ crystals of the same thickness), our
results indicate that monolayer jacutingaite should provide an excellent
platform to investigate transport in 2D quantum spin Hall systems.
