  Axions are a well-motivated dark matter candidate, with a host of experiments
around the world searching for direct evidence of their existence. The ORGAN
Experiment is a type of axion detector known as an axion haloscope, which takes
the form of a cryogenic resonant cavity embedded in a strong magnetic field.
ORGAN recently completed Phase 1a, a scan for axions around 65 \textmu eV, and
placed the most stringent limits to date on the dark matter axion-photon
coupling in this region, $|g_{a\gamma\gamma}|\leq 3\times 10^{-12}$. It has
been shown that axion haloscopes such as ORGAN are automatically sensitive to
other kinds of dark matter candidates, such as dark photons, scalar
field/dilaton dark matter, and exotic axion-electromagnetic couplings motivated
by quantum electromagnetodynamics. We compute the exclusion limits placed on
these various dark matter candidates by ORGAN 1a, and project sensitivity for
some future ORGAN phases. In particular, the dark photon limits are the most
sensitive to date in some regions of the parameter space.
