Ruby is a valuable red gem found in small clusters within bauxite. A given cluster may also contain a single star ruby. Aside from the colour, rubies are exactly identical to sapphires, including the value and physical characteristics (this implies that rubies are not magma-safe, melting at 11500 °U ). Rubies are also exactly identical to star rubies aside from the location and value.
In Real Life
"Ruby" is a type of red corundum (aluminum oxide: Al2O3); any colored corundum besides red is called a sapphire. Unlike in-game, rubies do not occur within bauxite in real life.
[SOLID_DENSITY:4005] Common to corundums. Range 3960 - 4050