Search results
Results from the WOW.Com Content Network
Lustre (British English) or luster (American English; see spelling differences) is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the Latin lux , meaning "light", and generally implies radiance, gloss, or brilliance.
Crocoite is commonly found as large, well-developed prismatic adamantine crystals, although in many cases are poorly terminated. Crystals are of a bright hyacinth-red color, translucent, and have an adamantine to vitreous lustre. On exposure to UV light some of the translucency and brilliancy is lost.
Christite has an adamantine luster and leaves behind an orange streak. [3] Its crystal system is monoclinic with possible crystal classes of twofold symmetry, mirror plane symmetry, and twofold with a mirror plane. This means it can have radial symmetry, mirror plane symmetry, or mirror plane symmetry perpendicular to the two-fold axis. [5]
Aleutite occurs as individual crystals in the masses of polycrystalline anhydrite. Aleutite is dark red, with reddish black streak, and has an adamantine luster. It is brittle with no visible cleavage observed. Parting was not observed, and its fracture is uneven. The density could not be measured due to lack of sufficient material.
The luster of a diamond is described as "adamantine", which simply means diamond-like. Reflections on a properly cut diamond's facets are undistorted, due to their flatness. The refractive index of diamond (as measured via sodium light, 589.3 nm) is 2.417. Because it is cubic in structure, diamond is also isotropic
For example, anatase is less hard (5.5–6 vs. 6–6.5 on the Mohs scale) and less dense (specific gravity about 3.9 vs. 4.2) than rutile. Anatase is also optically negative, whereas rutile is optically positive. Anatase has a more strongly adamantine or metallic-adamantine luster than that of rutile as well. [8]
This page was last edited on 26 March 2018, at 05:55 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may ...
Murdochite is an opaque mineral that exhibits a black color, adamantine luster, black streak, and isotropic optical class. [11] Samples from T. Khuni mine indicate that polished sections of murdochite resemble the color and reflectivity of magnetite but vary because of zoning. [10]