Obsidian. It has very fine grain or is amorphous, and it has a conchoid fracture, so it can be worked to a sharp edge and point. Gabbro, on the other hand, has a very coarse grain and it difficult to get and edge or point on at all.
No. Gabbro is mafic-ultramafic. An example of a felsic rock would be a granite or rhyolite.
Gabbro is an igneous rock, and therefore does not have a parent rock as would a metamorphic rock. Gabbro is an intrusive igneous rock formed from the slow cooling and solidification of mafic magmas deep underground.
The ferromagnesian minerals in the gabbro and basalt are subject to oxidation and chemical breakdown.
Granite is a coarse grained igneous rock without Pyroxene.
Granite and gabbro are the two biggies, granite being formed underground by felsic magma, and gabbro being formed underground by mafic magma. Diorite and peridotite are two others.
Obsidian
Basalt and pumice.
Rocks formed from solidified molten rock are classified as igneous rock. Examples would be basalt, granite, gabbro, pumice, obsidian, and rhyolite.
When you crushed Gabbro you would obtainOlivine, Pyroxene(Augite), and Plagioclase
Any rock that erupted on (lava) or within the Earth or crystallized from molten rock (magma). Such rock would fall into two categories: Intrusive (crystallized within the Earth), granite, gabbro, diorite, pegmatite, peridotite and extrusive (erupted and crystallized on the surface) rhyolite, andesite, obsidian, basalt, tuff and pumice.
No. Gabbro is mafic-ultramafic. An example of a felsic rock would be a granite or rhyolite.
Gabbro is an igneous rock, and therefore does not have a parent rock as would a metamorphic rock. Gabbro is an intrusive igneous rock formed from the slow cooling and solidification of mafic magmas deep underground.
The ferromagnesian minerals in the gabbro and basalt are subject to oxidation and chemical breakdown.
In the 1800's, many Native Americans would sharpen obsidian into spear tips.
Granite is a coarse grained igneous rock without Pyroxene.
Granite and gabbro are the two biggies, granite being formed underground by felsic magma, and gabbro being formed underground by mafic magma. Diorite and peridotite are two others.
A:Carbon-14 dating could not be used directly from the arrowhead itself. However, the bones associated with the arrowhead could be dated by this method, if they are sufficiently recent for this method. If the arrowhead is properly associated with the bones, you would then know its age.