“Translucent:” through which we see light.
“Opaque:” through which we can see nothing.
“Brilliant:” reflecting or refracting the light in rays and flashes.
“Vitreous:” glassy in its texture.
“Conchoidal:” convex, like the outside of a shell.
“Momentum:” the result of the combined weight and velocity of a body in motion.
GEOLOGICAL STRATA referred to in this Volume, arranged in their descending order.
| Names of Strata. | Mineral products. |
|---|---|
| Lava | Pumice-stone, which is its froth or scum. |
| Granite | Corundum, sapphires, felspar. |
| Old Red Sandstone | Fossil ichthyolites. |
| Carboniferous Series | Coal, lignites, jet. |
| New Red Sandstone | Jaspers, fossilized wood. |
| Lias of the Oolite | Fossil “Saurians.” |
| Wealden | Fossil reptiles and mammals. |
| Gault | Crystals, flint-nodules, choanites, echini, cray-fish, lignites. |
| Greensand | |
| Chalk | |
| Tertiary Sands | Amber, carnelians, fossil shells. |
| Clays |