Metallic gold alloys easily with mercury, so it can be dissolved by mercury.
It also alloys easily, i.e. it is dissolved, with other liquid metals, e.g. silver, copper, indium etc., but that is less obvious than with mercury, because those metals must first be heated to great temperatures, to become liquid, before dissolving gold.
The relation with arsenic is different. It is an affinity between ionic gold and arsenic, not between metallic gold and arsenic.
The gold ions are very big, among the biggest metallic ions. Because of that, the gold ions have great affinity only for some big anions (negative ions), i.e. for the ions of arsenic or of tellurium, which have approximately the same size.
This is in contrast with the smaller ions of silver and copper, which have great affinity with the smaller anions of sulfur.
It is well known that the gold ions have the greatest affinity for the anions of the size of arsenic and tellurium. Tellurium has an even greater affinity for gold than arsenic, but tellurium is extremely rare at the surface of the Earth. Due to the rarity of tellurium, even if minerals with gold and tellurium are well known they are less frequently found than those were gold is associated with arsenic.
While the maximal affinity of gold with tellurium and arsenic has been well known, this research has elucidated details of the mechanism how this creates arsenical minerals rich in gold, which may help in the prospection for such minerals.
Because gold is normally much more scarce in the environment than arsenic and than other metals with which arsenic combines easily, the minerals with arsenic and gold are seldom straightforward combinations of arsenic and gold, but as explained in the article, gold infiltrates arsenides of other metals (usually of iron, whose arsenide is the most abundant).
In Kalgoorlie, Australia, gold telluride was not recognized as such, but was instead misidentified as pyrite and was used as a paving material. The streets were literally paved with gold (since recovered).
