the part of the wortd "oid" literally means "form of"
mineraloid means "form of mineral"
it does in fact form crystals in its solid form!
Mercury is classified as a "metallic mineral"
Metallic Minerals List
It is the only liquid metal at room temperature
it is known as a secondary "mineral"
Pretty much every reputable mineral guide lists it as a mineral even though it is a "mineraloid"
It falls under the same laws as other metallic minerals in regards to mining law.
In the
Danaclassifacation system it is actually in the same catagory as gold
As far as dredging goes it falls under the same laws. You can file a claim to mine it. Considering that can only be done for "valuable minerals"
For all intents and purposes Mercury is a mineral
It is a mineral and you can not legally dredge for it in California