Hard.
lustre
The word is luster.
it is shiny
slickly shiny gray
slickly shiny gray
It will be shiny or smooth and its a lighter color
quartz
Quartz has a nonmetallic, vitreous luster.
Quartz.
Shiny metal is a physical property because it can be observed without changing the chemical composition of the metal. It is a characteristic related to how light interacts with the surface of the metal.
Quartz typically has a vitreous or glassy luster, which gives it a shiny and reflective appearance. This luster is a result of the crystal structure of quartz and its ability to reflect light.
To be shiny is a physical property.