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
USS Heliotrope (1863) USS Heliotrope (1863) USS "Heliotrope" (1863) was a wooden steamer acquired by the Union Navy for use during the American Civil War. In addition to patrol duty, "Heliotrope" performed other services, such as towing and dispatch running. "Heliotrope", a wooden steamer, was originally named "Maggie Baker", and was purchased by the Navy from her owner, Stacey Pitcher, at New York City on 16 December 1863. Renamed "Heliotrope", she commissioned at New York Navy Yard 24 April 1864. "Heliotrope" was assigned initially to the North Atlantic Blockading Squadron, and sailed soon after her commissioning to Hampton Roads, Virginia, where she served