To increase the amount of virtual memory go to Control Panel > System > Advanced > Performance > Settings > Advanced > Virtual Memory Change > Custom Size > adjust as needed. 2 times your physical RAM is a good minimum and 3 times your physical memory in MB is good for your maximum.
The three different types of lava differ in composition and flow rate. Rhyolitic lava is the slowest moving type of lava, since it has a high viscosity due to a high silica concentration. Basaltic lava is the fastest moving lava because of its low viscosity resulting from a low silica content.
Over 700 different types of igneous rocks have been discovered to date. These vary in terms of appearance, grain size and amount of time that it takes for the lava to cool. A common igneous rock rule is that if lava cools at a faster rate, the rock formed will have finer grains and have a glassy appearance; if rock cools at a slower rate, the grains will be larger and more coarse.