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
Heliotrope (building) waste composting. At the same time that Freiburg’s Heliotrope was built, Hansgrohe contracted Rolf Disch Solar Architecture to design and build another Heliotrope to be used as a visitor’s center and showroom in Offenburg, Germany. A third Heliotrope was then contracted and built in Hilpoltstein, Bavaria to be used as a technical dental laboratory. Disch’s unique design accommodates different utilization from private residences to laboratories, and nevertheless maintains the structure’s positive energy balance. In addition to the original Heliotrope design, Rolf Disch has drawn plans for larger versions of the project to be built as a rotating hotel, which gives