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Lustre (mineralogy)

Lustre or luster 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", implies radiance, gloss, or brilliance. A range of terms are used to describe lustre, such as earthy, metallic and silky; the term vitreous refers to a glassy lustre. A list of these terms is given below. Lustre varies over a wide continuum, so there are no rigid boundaries between the different types of lustre; the terms are combined to describe intermediate types of lustre. Some minerals exhibit unusual optical phenomena, such as asterism or chatoyancy. A list of such phenomena is given below. Adamantine minerals possess a superlative lustre, most notably seen in diamond; such minerals are transparent or translucent, have a high refractive index. Minerals with a true adamantine lustre are uncommon, with examples being cerussite and cubic zirconia. Minerals with a lesser degree of lustre are referred to as subadamantine, with some examples being garnet and corundum.

Dull minerals exhibit little to no lustre, due to coarse granulations which scatter light in all directions, approximating a Lambertian reflector. An example is kaolinite. A distinction is sometimes drawn between dull minerals and earthy minerals, with the latter being coarser, having less lustre. Greasy minerals resemble grease. A greasy lustre occurs in minerals containing a great abundance of microscopic inclusions, with examples including opal and cordierite, jadeite. Many minerals with a greasy lustre feel greasy to the touch. Metallic minerals have the lustre of polished metal, with ideal surfaces will work as a reflective surface. Examples include galena and magnetite. Pearly minerals consist of thin transparent co-planar sheets. Light reflecting from these layers give them a lustre reminiscent of pearls; such minerals possess perfect cleavage, with examples including stilbite. Resinous minerals have the appearance of chewing gum or plastic. A principal example is amber, a form of fossilized resin.

Silky minerals have a parallel arrangement of fine fibres, giving them a lustre reminiscent of silk. Examples include asbestos and the satin spar variety of gypsum. A fibrous lustre has a coarser texture. Submetallic minerals are duller and less reflective. A submetallic lustre occurs in near-opaque minerals with high refractive indices, such as sphalerite, cinnabar and cuprite. Vitreous minerals have the lustre of glass; this type of lustre is one of the most seen, occurs in transparent or translucent minerals with low refractive indices. Common examples include calcite, topaz, beryl and fluorite, among others. Waxy minerals have a lustre resembling wax. Examples include chalcedony. Asterism is the display of a star-shaped luminous area, it is seen in some rubies, where it is caused by impurities of rutile. It can occur in garnet and spinel. Aventurescence is a reflectance effect like that of glitter, it arises from minute, preferentially oriented mineral platelets within the material. These platelets are so numerous that they influence the material's body colour.

In aventurine quartz, chrome-bearing fuchsite makes for a green stone and various iron oxides make for a red stone. Chatoyant minerals display luminous bands; such minerals are composed of parallel fibers, which reflect light into a direction perpendicular to their orientation, thus forming narrow bands of light. The most famous examples are tiger's eye and cymophane, but the effect may occur in other minerals such as aquamarine and tourmaline. Colour change is most found in alexandrite, a variety of chrysoberyl gemstones. Other gems occur in colour-change varieties, including sapphire, spinel. Alexandrite displays a colour change dependent upon light, along with strong pleochroism; the gem results from small-scale replacement of aluminium by chromium oxide, responsible for alexandrite's characteristic green to red colour change. Alexandrite from the Ural Mountains in Russia is green by red by incandescent light. Other varieties of alexandrite may be yellowish or pink in daylight and a columbine or raspberry red by incandescent light.

The optimum or "ideal" colour change would be fine emerald green to fine purplish red, but this is rare. Iridescence is the'play' or'fire' of rainbow-coloured light caused by thin regular structures or layers beneath the surface of a gemstone. Similar to a thin film of oil on water, these layers interfere with the rays of reflected light, reinforcing some colours and cancelling others. Iridescence is seen at its best in precious opal. Schiller, from German for "colour play", is the metallic iridescence originating from below the surface of a stone that occurs when light is reflected between layers of minerals, it is seen in moonstone and labradorite

2018 Colorado State Rams football team

The 2018 Colorado State Rams football team represented Colorado State University during the 2018 NCAA Division I FBS football season. The Rams were led by fourth-year head coach Mike Bobo and played their home games at Sonny Lubick Field at Canvas Stadium in Fort Collins, Colorado as members of the Mountain Division of the Mountain West Conference, they finished the season 3–9, 2–6 in Mountain West play to finish in fifth place in the Mountain Division. The Rams finished the 2017 season 7–6, 5–3 in Mountain West play to finish in a tie for second place in the Mountain Division, they were invited to the New Mexico Bowl. Listed in the order that they were released During the Mountain West media days held July 24–25 at the Cosmopolitan on the Las Vegas Strip, the Rams were predicted to finish in third place in the Mountain Division; the Rams had one player selected to the preseason all-Mountain West team. Source

Big Dance Theater

Big Dance Theater is a New York City-based dance theater company known for its experimental theater works combining dance and literature. It is led by Artistic-Director Annie-B Parson, who founded Big Dance Theater in 1991 with Molly Hickok and Paul Lazar. For more than 25 years, Big Dance Theater has worked to create over 20 dance/theater works, generating each piece over months of collaboration with its associate artists, a long-standing, ever-evolving group of actors, dancers and designers, they have been commissioned by the Brooklyn Academy of Music, The National Theater of Paris, The Japan Society, The Walker Art Center and have performed in many venues, including the Brooklyn Academy of Music, Dance Theater Workshop, The Kitchen, Classic Stage Company, Japan Society, Jacob's Pillow Dance Festival, the Chocolate Factory, The Museum of Contemporary Art in Chicago, Walker Art Center, Yerba Buena, On the Boards, New York Live Arts, UCLA Live, The Spoleto Festival USA, at festivals internationally in Europe and Brazil.

Founded in 1991, Big Dance Theater is known for its inspired use of dance, music and visual design. The company works with wildly incongruent source material and braiding disparate strands into multi-dimensional performance. Led by Artistic Director Annie-B Parson, Big Dance has delved into the literary work of such authors as Twain, Wellman and Flaubert, dance is used as both frame and metaphor to theatricalize these writings. Parson describes Big Dance as "a group of people who are interested in pushing dance into the theatrical realm and pushing theater into the dance realm." To her, Big Dance has a "total greediness for all the pleasures of theater and dance" The work of Big Dance is always non-linear, disinclined to have a narrative Though the lack of a linear story leaves critics bewildered, the intentionality, technical precision and the ambitious scope of the worlds they create guarantees that the critic don't mind feeling lost. In the words of critic Helen Shaw, "the difference between a Big Dance Theater event and work by someone like, Richard Foreman is that Big Dance will send you into a trance state-and shake its finger at you and wink."Critic Helen Shaw wrote of Big Dance as a "fluid gang of performers and designers clustered around the married co-directors, choreographer-director Annie-B Parson and actor-director Paul Lazar.

The company is – as it says on the bottle – a hybrid group, ignoring customary divides between dance and theatre." The Company began as a loose but dedicated and generative alliance, made up of women including Stacy Dawson, Molly Hickok, Tymberly Canale, Cynthia Hopkins, Rebecca Wisocky, Kourtney Rutherford. This group flowed with others joining in over the years. Sacrifice was the first of Parson's large scale works and her first work at Dance Theater Workshop, curated by David White, who would champion Parson's work for decades. Set in something like a beauty parlor, this piece incorporated text from Harold Pinter and was accompanied by a score of repetitive gestures executed by five pairs of men and women; the Gag premiered at Dance Theater Workshop in 1993. This large-scale work was based on the myth of the Cassandra figure in Greek mythology and the piece incorporated the text of radical feminist writer Andrea Dworkin. Molly Hickok played the central role, starting a decades-long collaboration between Parson.

The piece was inspired by the writings Christa Wolff with text by Aeschylus and Marguerite Yourcenar. It featured original music by Walter Tompson, performed live. Four monitors on the floor included footage of small scampering animal babies; the New York Times described The Gag as “a bouillabaisse of a theater-dance piece…There’s a little Greek tragedy, a bit of Harold Pinter, a dab of Tennessee Williams and a large dose of fashion and comic high jinks.” Presented by the Cucaracha Theater, made for NYU Students, Bremen Freedom, by the west-German playwright Rainer Fassbinder, told the story of Geesche, a woman so sick of being controlled by the men in her life that she methodically poisoned them, herself. The Village Voice wrote that the production included “a little cabaret shtick, some cross-dressing, a few dollops of disjunction, plenty of stylized tableau-making, a pinch of Catholic imagery, several actresses playing the same role, a bit of lovely/creepy choral singing, heaps of that unmotivated goofy dancing that made Brace Up such a hoot.”

Although the reviews referenced some of the performative similarities to Cabaret, the Village Voice insisted that “these kids come on like innovators, not imitators, they know how to deliver a spectacle piping hot.” Though choreographic, this work was the first “play” that Big Dance, a dance based company, had staged. In 1995, Parson was featured in the Young Choreographers and Composers at the American Dance Festival in North Carolina, she was paired with composer Richard Einhorn and the two created “City of Brides,” performed by five barefoot women and accompanied by a complex score for piano and cello based on Stravinsky's Les Noces. This would be the first “erasure” work, Parson's term for choreographing to a piece of music and erasing it, so that while the music was never heard by the audience, the movement material, inspired by his rhythms endured; the News & Observer wrote that “Parson is a talent to be reckoned with.” A reviewer for the Toronto Arts Journal CallTime wrote that Pa