Question

What is the structure and texture of: 1 hornblendite rock 2 pumice rock 3 quartz syenite rock 4 rhyolite rock 5 volcanic breccia rock 6 clay shale rock 7 jasper rock 8 mylonite rock 9 tremolite schist rock 10 crystal marble rock

Answer 1

1. Hornblende Rock Hornblende is a field and classroom name used for a group of dark-colored amphibole minerals found in many types of igneous and metamorphic rocks. These minerals vary in chemical composition but are all double-chain inosilicates with very similar physical properties. A generalized composition for the hornblende group is shown belo. Hornblende minerals as a group are relatively easy to identify. The diagnostic properties are their dark color (usually black) and two directions of excellent cleavage that intersect at 124 and 56 degrees. The angle between the cleavage planes and hornblende's elongate habit can be used to distinguish it from augite and other pyroxene minerals that have a short blocky habit and cleavage angles intersecting at about 90 degrees. The presence of cleavage can be used to distinguish it from black tourmaline that often occurs in the same rocks.

eruptions. It Pumice is a light-colored, extremely porous igneous rock that forms during explosive volcanic eruptions. It is used as aggregate in lightweight concrete, as landscaping aggregate, and as an abrasive in a variety of industrial and consumer products. Many specimens have a high enough porosity that they can float on water until they slowly become waterlogged. unti they slowiy bee os. Many specamendscaping agregate, and as Uses of Pumice The largestuse of pumice in the United States is the production of lightweight concrete blocks and other lightweight concrete products. When this concrete is mixed, the vesicles remain partially filled with air. That reduces the weight of the block. Lighter blocks can reduce the structural steel requirements of a building or reduce the foundation requirements. The trapped air also gives the blocks a greater insulating value The second most common use of pumice is in landscaping and horticulture. The pumice is used as a decorative ground cover in landscaping and planters. It is used as drainage rock and soil conditioner in plantings. Pumice and scoria are also popular rocks for use as substrates in hydroponic gardening. Pumice has many other uses. Together these account for less than a few percent of consumption in the United States, but these are the products that most people think of when they hear the word "pumice Lots of people have found small pumice pebbles in the pockets of brand new "stone washedjeans," and almosteveryone has seen the famous "Lava Soap" that uses pumice as an abrasive. Below we list these and some of the other minor uses of pumice (in no particular order). [5] . anabrasive in conditioning "stone washed" denim . anabrasive in bar and liquid soaps such as "Lava Soap" . anabrasive in pencil erasers . anabrasive in skin exfoliating products . a fine abrasive used for polishing a traction material on snow-covered roads a traction enhancer in tire rubber anabsorbent in cat litter . a fine-grained filter media . a lightweight filler for pottery clay

enite Rock Syenite, any of a class of intrusive igneous rocks essentially composed of an alkali feldspar and a ferromagnesian mineral. A special group of alkali syenites is characterized by the presence of a feldspathoid mineral such as nepheline, leucite, cancrinite, or sodalite (see nepheline syenite). Chemically, syenites contain a moderate amount of silica, relatively large amounts of alkalies, and alumina. The name was first used by Pliny the Elder agrup of alkali syenites is chodalite (see nepheline SVennte The name The texture of syenites, like that of granite, is granular, and these rocks differ from granite only by the absence or scarcity of quartz. The alkali feldspars present may include orthoclase, perthite, albite, or, more rarely, microcline; the ferromagnesian mineral may be biotite, hornblende, or pyroxene. In the alkali syenites, the amphiboles or pyroxenes frequently contain sodium. The more normal syenites are divisible according to their prevalent dark-coloured mineral into augite-, hornblende-, and biotite-svenites; but, like granites, syenites are also divisible according to the type of alkali feldspar into potash and soda syenites. The accessory constituents include titanite, apatite, zircon, magnetite, and pyrites. Syenites are much less common than granites and diorites. The rocks known as nordmarkite and pulaskite are soda syenites. Rocks transitional between syenites and diorites are known as monzonites

4. Rhyolite Rock Rhyolite is an extrusive igneous rock with avery high silica content. It is usually pink or gray in color with grains so small that they are difficult to observe without a hand lens. Rhyolite is made up of guartz, plagioclase, and sanidine, with minor amounts of hornblende and biotite. Trapped gases often produce vugs in the rock. These often contain crystals, opal, or glassy material Uses of Rhyolite Rhyolite is a rock that is rarely used in construction or manufacturing. It is often vuggy or highly fractured. Its composition is variable. When better materials are not locally available, rhyolite is sometimes used to produce crushed stone. People have also used rhyolite to manufacture stone tools, particularly scrapers, blades, and projectile points. It was probably not their material of choice, but a material used out of necessity

5. Breccia Rocks clastic sedimentary rocks that are composed of Breccia is a term most often used for large angulair fragments (over two millimeters in diameter). The spaces between the large angular fragments are filled with a matrix of smaller particles and a mineral cement that binds the rock together. Uses of Breccia? The rock, breccia, has very few uses. It can be used as fill or road base where the technical requirements are minimal. It is rarely used in important projects because its composition, degree of cementation and competence are highly variable. The word "breccia" is used as a trade name for a group of dimension stone products with a broken, angular pattern. Names such as "Breccia Oniciata," "Breccia Pernice," and "Breccia Damascata" are cut and polished limestones and marbles that reveal a broken, angular pattern. These breccias are used as architectural stones for interior building veneers, tiles, window sills, and other decorative applications. These are proprietary names applied to the rock from specific quarries.