Chalcedony to as prase. However, the term prase is also used to describe green quartz, and to a certain extent is a color-descriptor, rather than a rigorously defined mineral variety.) Blue-colored chalcedony is sometimes referred to as "blue chrysoprase" if the color is sufficiently rich, though it derives its color from the presence of copper and is largely unrelated to nickel-bearing chrysoprase. Heliotrope is a green variety of chalcedony, containing red inclusions of iron oxide that resemble drops of blood, giving heliotrope its alternative name of bloodstone. In a similar variety, the spots are yellow instead, known as plasma. Moss agate
Aluminium alloy inclusions formed when aluminium became colder. Fluxing salt, like chlorides are also liquid inclusions. They come from flux treatments added to the melt for cleaning. Titanium boride (TiB) is intentionally added to the melt for grain refinement to improve mechanical properties. Phosphorus is added to the melt hypereutectic alloys for modification of the silicon phase for better mechanical properties. This creates AlP inclusions. Boron treatment inclusions ( (Ti, V)B ) form when boron is added to the melt to increase conductivity by precipitating vanadium and titanium. The following inclusion types can also be found in aluminium alloys: alumina needles (Al2O3), nitrides