Deprecated function: Array and string offset access syntax with curly braces is deprecated in include_once() (line 20 of /home/raw3y9x1y6am/public_html/includes/file.phar.inc).
Hydrothermal veins are a combination of the two ways that crystals form. Magma contains water as well as molten rock. Because it is underground, and under tremendous pressure, the water stays a liquid. At very high temperatures and pressure, that water can dissolve quite a few minerals. As the magma cools, the last part that is still a liquid is the quartz and the high temperature/high pressure water. They flow into cracks in the surrounding rocks, where they cool. The quartz starts to solidify quickly, but the hot water keeps some of it dissolved.
These are ripple marks in beach sand, made by the wind. Similar ripples can be seen in deserts, and even in large playground sandboxes. What causes the ripples to be so evenly spaced?