1 When Snapchat decides to IPO and sell stock to the public on a stock exchange â NYSE, Nasdaq, etc.  If somehow you knew the Snapchat team and got a chance to invest with them. I.E. you give them money directly so they can invest it back into the company and in return they give you stock.
Extrusive igneous rocks, also known as volcanic rocks, are formed at the crust's surface as a result of the partial melting of rocks within the mantle and crust. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth's surface. The magma, which is brought to the surface through fissures or volcanic eruptions, solidifies at a faster rate.
Some extrusive igneous rocks cool so rapidly that crystals do not develop at all. These form a glass, such as obsidian (Figure 4.14). Others, such as pumice, contain holes where gas bubbles were trapped when the material was still hot and molten.The holes make pumice so light that it actually floats in water. The most common extrusive igneous rock is basalt, a rock that is especially common below the oceans (Figure 4.15).Figure 4.13: Extrusive igneous rocks form after lava cools above the surface. The lave spills out from the Earth at a volcano.he holes make pumice so light that it actually floats in water. The most common extrusive igneous rock is basalt, a rock that is especially common below the oceans (Figure 4.15). Figure 4.13: Extrusive igneous rocks form after lava cools above the surface.