Evenkite - the mineral with the lowest SG that stales is aware of.

Mercury - mineral and native element - NOT the 'heaviest' of either. Any statement to the contrary is a stales furphy.

Gold - also a mineral and native element - also NOT the heaviest of either.

Osmium - an element (Os) - but not a mineral and not found in the elemental state in nature.

Iridium - Confusing. An element (Ir) - but not found in its elemental form in nature. A different beast, 'Iridium' (formerly known as Osmiridium) is a mineral with the formula (Ir,Os,Ro) - ie it's an alloy of three metallic elements, iridium, osmium and rhodium. Iridium (the mineral) IS the heaviest mineral that stales is aware of - having now been brought into line.

In the mineral world one always uses a leading capital letter when spelling the mineral species - thus usage would be: ....the heaviest of minerals is Iridium, which consists of iridium, osmium and rhodium.

Any other contenders or do we now have it?

stales