Dull luster

Pyrolusite is a black, opaque mineral with a metallic luster and is frequendy soft enough to soil the fingers. Most varieties contain several percent water. Pyrolusite is usually a secondary mineral formed by the oxidation of other manganese minerals. Romanechite, a newer name for what was once known as psilomelane [12322-95-1] (now a group name) (7), is an oxide of variable composition, usually containing several percent water. It is a hard, black amorphous material with a dull luster and commonly found ia the massive form. When free of other oxide minerals, romanechite can be identified readily by its superior hardness and lack of crystallinity. 

The other elements, the ones to the right of the line and metalloids and also including hydrogen are classified as the nonmetals. The nonmetals have properties that are opposite of the metals. Many are not solid, they have a dull luster, are nonconductors, and are neither malleable nor ductile. The nonmetals tend to gain electrons in chemical reactions. 

The common form of asphalt is a black, compact, amorphous, brittle mass of dull luster, which breaks showing a polished surface and fuses at 188-90°F (ca 87°), d 1.40-1.42 at 77°F (25°C) and Moh s hardness 1 to 2... 

Broken surfaces have a brilliant, glassy luster and are jet-black in color with a perfect conchoidal fracture. Remnants of the precataclasis bounding surface of each nodule retain a dull luster owing to a closely pitted, etched surface. Maximum size of the composite nodule ranges up to 5 cm. but can be as little as 0.5 cm. 

Chrysocolla is generally some shade of blue or green but if impure maybe brown or black. It has a characteristic conchoidal fracture hardness, 2-4 sp gr. 2.24 vitreous to dull luster translucent to opaque. 

Cannel coal Nonbanded coal in which the liptinite is predominantly sporinite. Fusain coal layers composed of chips and other fragments in which the original form of plant tissue structure is preserved commonly has fibrous texture with a very dull luster friable and resembles charcoal commonly concentrated in bedding layers or lenses that form planes of weakness in coal and thus is often exposed on bedding surfaces of broken coal. 

Properties Brilliant black to blackish-red or brick-red mineral with brown to cherry-red streak and metallic to dull luster. D 4.9-53, Mohs hardness 6. Noncombustible. 

Properties Black color, brownish-black streak, pitchy to dull luster. Mohs hardness 5.5, d 6.5-8.5. 

Properties Iron-black to dark steel-gray or bluish mineral black or bluish-black streak metallic or dull luster. D 4.73 1.86, Mohs hardness 2-2.5. Soluble in hydrochloric acid. 

Both boghead coal and cannel coal contain nitrogen, oxygen, and sulfur in addition to carbon and hydrogen (Table 4.6). They have a dull luster and fracture in a conchoidal pattern (i.e., the fracture surface has small rounded elevations and depressions). Cannel coal is black whereas boghead coal is in dull brown color, and splinters of these coals are easily ignited in fact, cannel coal bums with a long and steady flame from which the name is derived (candle). 

Non-metal - me-t l (ca. 1864) n. An element with generally low electrical and thermal conductivities, dull luster, and a high ionization energy, electron affinity and electronegativity. 

Peau de sole n. A heavyweight, soft satin of silk or manufactured fiber with a fine cross rib and a dull luster. The term is French for skin of silk . 

Sharkskin shark- skin n(1851) (1) An irregularity of the surface of an extrudate in the form of finely spaced sharp ridges perpendicular to the extrusion direction, believed to be caused by a relaxation effect on the melt at the die exit. (2) A hard-finished, twill fabric, woolen or worsted, made of simple weaves with a two-color arrangement of warp and filling yarns. (3) A plain-weave sportswear fabric made of dull-luster acetate or triacetate yarns. 

Rubber fibers are manufactured by several companies as rubber fiber or under trade names such as Buthane, Contro, Hi-Flex, Lactron, Lastex, and Eaton. Rubber fibers show good elastomeric properties and reasonable aesthetic properties particularly as the eore of a textile yarn structure. Rubber fibers usually have a dull luster due to the additives and fillers within the fiber. The fiber has poor resistance to household chemicals. 

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