In dwarven heraldry, on the other hand, these rules and tinctures are quite different. Whereas human heraldry has only two metals, dwarven heraldry has platinum, electrum, silver, gold, copper, bronze, iron, and tin. "Bronze" in this case is a fine diamond-checkered pattern of copper and tin, whereas "electrum" is a similar pattern of silver and gold; they can thus be seen as analogous to the human furs, although dwarven heralds will vehemently resist such comparisons and strenuously defend their classification as metals. Metals are rendered in metallic paints (which are in some cases more expensive than the metals themselves) or in the actual metals.
There are no general rules about mixing colors and metals, although there are rules about specific combinations of tinctures; topaz should never be placed atop gold (and vice versa), diamond and platinum should not be mixed, nor should platinum and silver.
Ordinaries, divisions, creatures, and objects are generally the same in both human and dwarven heraldry, although the terms are, naturally, translated into dwarvish. Nautical creatures and objects (anchors, fish, etc.) are never seen on dwarven heraldry, but objects like anvils, hammers, axes, and mine carts abound.
Finally, the standard shape for dwarven arms is the round shield (as opposed to other types common in human heraldry such as the escutcheon or lozenge).
Humans often have difficulty distinguishing between some of the tinctures used in dwarven heraldry; platinum and silver, for example. Dwarven heralds scoff at such complaints, however, pointing out that dwarven heraldic devices were originally designed to appeal to refined dwarven sensibilities and not the eyes of a race that "can't tell pyrite from gold."
(Thanks to Inkwell Ideas' excellent Coat of Arms Visual Designer, which was used to create most of the images above, with modifications to shield shape made in GIMP.)