Osmium is the densest metal, and it is very strong and also very heavy. But is mostly used in alloys to increase strength, no pure metal is harder than the strongest of alloys.
The hardest practical metal is high carbon steel. Titanium is lighter, but has more volume with equivalent strength. Most alloys are either too heavy, too brittle or too large to be practical. For example, making a sword of pure diamond would be the hardest type of sword (And certainly the most expensive) yet one decent hit could crack it because it is not malleable enough. There have been experiments with hybrid materials like a carbon fibre tang with a steel blade, but nothing really happening yet.
Diamonds is not a stone it's crystal actually. But the hardest stone is granite stone.
the hardest thing about arthritis is dealing with the horrible pain
yes
Lutemium
There is no metal by the name 'thompson'.
Caesium (or cesium) is the softest metal.
tungsten
yes it is
titanium
Chromium is the hardest metal; the Mohs hardness of osmium is 7 and the Mohs hardness of chromium is 8,5.
diamond
If you mean literally hard, then metal coins (found in many countries) would be the hardest.
Tungsten.
sludge hammer
Gold is not the hardest metal. It is relatively soft compared to other metals. Metals like titanium, tungsten, and steel are harder than gold.