Slate is a rock, so you won't find it listed on the Mohs Scale, because that scale of hardness applies to minerals. I'll go out on a limb though, and suggest that slate is probably around 2 to 3 or so, but this will be variable, depending on the quality of the slate, and degree of weathering, etc.
The hardness of Limonite is 4 t0 5.5 on the mohs hardness scale.
It is about 2.5 in the Mohs Hardness Scale.
The fourth mineral on Mohs' Scale of Hardness is fluorite. It has a hardness of 4 on the scale.
The Mohs Scale of Hardness determines the hardness of minerals by scratching them with commonly found objects. The minerals are assigned a number which corresponds to their hardness; higher numbers indicate higher hardness.
The hardness is 6 on the MOHS scale
Slate, being a metamorphic rock, would not have a hardness listing on the Mohs scale of mineral hardness.
Diatomite has a hardness of around 5.5 on the Mohs scale of hardness.
It's called the Ore
The hardness of Limonite is 4 t0 5.5 on the mohs hardness scale.
Azurite has a hardness of 3.5 to 4 on the Mohs hardness scale.
flint is a type of quartz, so it has a hardness of about 7 on the mohs scale of hardness
The hardness is 3-4 on Mohs scale.
Nickel has a hardness of 4 on the Mohs scale.
Dolomite has a hardness of 3.5-4 on the Mohs scale of hardness.
The Mohs scale is used to determine the relative hardness of minerals.
This scale was proposed by the Austrian geologist Friderich Mohs.
Aluminum Oxide is roughly 8.5 - 9.0 on the hardness scale.