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 is a fracture test method. Liquid metal is cast into a mold containing notches. Once solidified, the resulting bar is bent to expose a fracture surface. The visual observation of inclusions on the fracture is used to determine a K-value for the melt and compared to a preset standard. This method is rather imprecise and therefore only suitable when metal contents large inclusions and inclusion clusters. The LiMCA method measures the total concentration and size distribution of inclusions present in aluminum alloys. Its measuring principle is based on an objective and user-independent method. The LiMCA CM system can characterize the