limestone's hardness is 3-4 and it does not have a luster it's main constituent is the mineral calcite, and has a vitreous or glass luster.
The color is clear, the hardness is the hardest thing in the world, and the luster is pearly.
"Tuff", a rock made up of volcanic ash and other things, is not a mineral, so it has no hardness index or luster.
luster
You can test its hardness on other minerals to find it hardness. It can help classify it better.
Plutonium is a silvery metal.- Vickers hardness: 255 - Brinell hardness: 242 - Mohs hardness: cca. 3,7
hardness and luster
hardness streak and luster and color
hardness streak and luster and color
Hardness Streak Luster Color
hardness
Glassy luster, Metallic luster and Waxy luster.