| Rock Class | Igneous Rock |
|
Rock Subclass
|
Volcanic (volcanic glass) |
| Origin | Hidalgo, Mexico |
| Size | 2.0-3.0cm |
Obsidian, or volcanic glass, is molten lava that has cooled quickly. Its composition is mainly silica oxides, being very similar to that of granite or rhyolite.
The rock includes a label with the name and origin and is attached to a cardboard box. 4 cm square.
*The price is per unit (a single cardboard box of the four shown in the image)
Since the rocks are natural, you will receive a piece similar to the one in the photograph. The samples come in cardboard boxes and are glued to a porex base with hot silicone; These can be removed using ethyl alcohol without damaging the mineral. The size is approximate.