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
Silicate mineral paint Silicate mineral paint Silicate mineral paints or mineral colors are paint coats with mineral binding agents. Two relevant mineral binders play a role in the field of colors: Lime and silicate. Under influence of carbon dioxide, lime-based binders carbonate and water silicate-based binders solidify. Together they form calcium silicate hydrates. Lime paints (aside of Fresco-technique) are only moderately weather resistant, so people apply them primarily in monument preservation. Mineral colors are commonly understood to be silicate paints. These paints use potassium water glass as binder. They are also called water glass paints or Keimfarben (after the inventor). Mineral silicate paint