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
Red diamond Red diamond A red diamond is a diamond which displays red color and exhibits the same mineral properties as colorless diamonds. Red diamonds are commonly known as the most expensive and the rarest diamond color in the world, even more so than pink diamonds or blue diamonds. Red diamonds, just like pink diamonds are greatly debated as to the source of their color, but the gemological community most commonly attributes both colors to gliding atoms in the diamond’s structure as it undergoes enormous pressure during its formation. Red diamonds are among the 12 colors of fancy color diamonds, and are