Gabbro, with its interlocking crystalline structure.
No, Limestone is harder than chalk.
gabbro
Gabbro is coarse textured.
Although gabbro is low in silica and has no quartz there are quartz gabbro's. Quartz gabbro's are thought to occur from magma that was over-saturated with silica.
Limestone is softer than marble, but harder than chalk.
No, Limestone is harder than chalk.
gabbro
Yes
dolomitic limestone is different from agricultural or hydrated limestone the difference is in the MgO content and hardness Dolomitic Limestone is harder than both and its MgO content is higher. The CaO is lower in Dolomitic limestone and High in the later.
Gabbro is a rock
Limestone would be potentially harder until the clay is fired. The problem we have here is that "clay" is an ambiguous term. There is no homogenous or standard formula for clay. However, clays can generally be formed and baked to become set and hard. This is called firing. Fired clay tends to be quite hard, and depending on the formula, might be harder than limestone.
Marble is formed when limestone is metamorphosed. This process occurs when the mineral calcite in limestone recrystallizes due to heat and pressure, resulting in a denser, harder rock with a crystalline structure.
Gabbro is coarse textured.
No. Gabbro is an intrusive igneous rock.
Limestone is softer than marble, but harder than chalk.
limestone
Although gabbro is low in silica and has no quartz there are quartz gabbro's. Quartz gabbro's are thought to occur from magma that was over-saturated with silica.