Wall and Ceiling Spray Texture is an unaggregated texture coating for interior, above-grade surfaces. Texture: Grain Size 1/256-2 mm. Rock Type Igneous, Sedimentary All Rights Reserved.Web Design by Hindsite Interactive, ©  2018 Textures3D. Organic sedimentary rocks such as coal, and some limestones are formed from the accumulation of plant or animal debris. Gypsum from New York: Selenite, a variety of gypsum from Penfield, New York. All Rights Reserved.Web Design by Hindsite Interactive. WE SHIP TO ALL 50 STATES, U.S. Texture material is pumped through a hose to a handheld trigger activated gun. Before drywall became widely used, building interiors were made of plaster. Second of all, no they aren't. Composition Hydrous calcium sulfate . Petrographically, four types of gypsum textures are also identified; alabastrine, porphyroblastic, fibrous and granular. The variety used in our wall panels and tiles is alabaster, a fine-grained white/lightly tinted gypsum material. Rock gypsum is a chemical precipitate formed by the evaporation of cencentrated solutions such as seawater. $23.99 $ 23. The line between A and A' indicates an unconformity. All Rights Reserved. It is designed for spray application over gypsum panel, concrete, and most other interior wall and ceiling surfaces. Description. Load up your texture brush. ), ©  2018 Textures-3D®. Alabaster gypsum jar: Jar made of beautiful translucent alabaster gypsum by David MacFarlane, photo copyright iStockphoto / David MacFarlane. Antelope Canyon. 99. Rock Gypsum Precipitation in salt lakes and inland seas. GYPSUM-PANEL TEXTURED CEILINGS PART 1 - GENERAL 1.1 SECTION INCLUDES A. No need to register, buy now! Related Images: texture rock stone background pattern 1,182 Free images of Rock Texture. Rocks are considered coarse grainded if you … Plaster is made with gypsum by heating it to approximately 300 degrees Fahrenheit, which forces out the majority of the water. Sheetrock Brand 50 lb. There are three basic types of sedimentary rocks. Ideal for interior walls in hotels, restaurants, hospitals, schools and even in home theatres, music rooms, and bedrooms. It has been around for millenniums. Composition of Major Fraction: Composition as Indicated in left column (prefix appropriate names for mixtures) Chiefly Calcite or Dolomite: Composition of Minor Fraction < 10% Minor Fraction : Limestone, Dolomite, Etc. Specimen is approximately 4 inches (10 centimeters) across. Texture a ceiling is probably much cheaper than installing beadboard, but it is not a piece of cake. Drywall -hung, taped, ready for texture – this is comparable to Level 3 Drywall -hung. (part 1) Crystalline, Clastic, Bioclastic, Oolitic, Etc. It forms in lagoons where ocean waters high in calcium and sulfate content can slowly evaporate and be regularly replenished with new sources of water. Other options New from $23.89. Gypsum is commonly as… These spray textures are ideal for use over properly prepared interior surfaces, including gypsum panels, concrete and plasters substrates. The textures shown can be used on either exterior or interiors. Based on the composition and foliated texture, this rock can best be identified as 6.Base your answer to the following question on the cross section below. An agricultural soil treatment. Dries white and is typically left unpainted on noncontact ceiling surfaces. We knew what we were looking for in quality and design, and we knew that the production factory would have to be technologically advanced. Metamorphic Rocks. The result is the accumulation of large beds of sedimentary gypsum. Rock gypsum is a chemical sedimentary rock. Two different grain sizes in an igneous rock indicate: a. two forms of metamorphism c. the rock cooled too slowly. answer choices . 56 80 4. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Rock gypsum superficially resembles chalk. Gypsum: Satin spar, a fibrous variety of gypsum from Derbyshire, England. Gypsum uses include: manufacture of wallboard, cement, plaster of Paris, soil conditioning, a hardening retarder in portland cement. Gypsum is the most common sulfate mineral. Specimen is approximately 3 inches (7.6 centimeters) across. The chemical difference is that gypsum contains two waters and anhydrite is without water. Specimen is approximately 2-1/2 inches (6.4 centimeters) across. Some texture can fit many room types, while several texture types can not work in several room types. Find the perfect rock gypsum stock photo. TEXTURES-3D® is honored to have been named the exclusive distributor and importer of the ARTPOLE COLLECTION of 3D hard rock gypsum in porcelain finish for the United States.The ARTPOLE COLLECTION is a design driven product that captures European artistry and craftsmanship with extreme detail. Hold the brush perpendicular to the wall and "stamp" the brush onto the wall. Figure 1. Rock gypsum’s color is often a mottled whitish-light grayish-light brownish. Des milliers de nouvelles images de grande qualité ajoutées chaque jour. CLASSIFICATION OF SEDIMENTARY ROCKS Based on the average grain size of the sediments Clastic rocks are … The medium texture provides a variety of decorating options and helps conceal minor surface defects. Texture arises because the gypsum forms stronger bonds between gypsum crystals than between the gypsum crystals and bassanite powder. Porphyritic. Provides a fast and easy application of light textures, and offers superior open time, excellent standout and low shrinkage to save on labor and preserve job profits. Rock gypsum, unlike rock salt, does not have a salty taste, and is softer (H = 2) - it can be scratched with a fingernail. Applying a texture to walls and ceilings creates a specific look, and builders can find an assortment of drywall textures and ceiling texture options from USG below. What Are Sedimentary Rocks? Huge collection, amazing choice, 100+ million high quality, affordable RF and RM images. No crystals were formed during the cooling process. ), 23.6"x23.6"x1.9" Panel@ $ 2. Trouvez des images de stock de Gypsum Board Texture en HD et des millions d’autres photos, illustrations et images vectorielles de stock libres de droits dans la collection Shutterstock. Tags: Question 60 . Specimen is approximately 3 inches (7.6 centimeters) across. 49.75=($12.86/sq.ft. Specific Gravity 2.3 - 2.4 . As a rock, gypsum is a sedimentary rock, typically found in thick beds or layers. This is a very common and basic texture, named because of its resemblance to the dimpled skin of an orange. It ranges in texture from massive/granular to fibrous depending on the size and shape of the gypsum crystals. It’s often used to cover imperfections in any drywall without the … A massive fine-grained white or lightly tinted variety of gypsum, called alabaster, has been used for centuries to create sculptures. It is usually microcrystalline and powdery looking (it's much finer-grained than typical rock salt deposits). basalt. Stone Concrete Wall. The result is the accumulation of large beds of sedimentary gypsum. 52 68 3. You are going to need a skill and need to find the perfect ceiling type for your room. rock 667 Gypsum 668 Salt 669 Interbedded sandstone and siltstone 670 Interbedded sandstone and shale 671 Interbedded ripple-bedded sandstone and shale 672 Interbedded shale and silty limestone (shale dominant) 680 ... 37.2—Metamorphic-rock, igneous-rock, and vein-matter lithologic patterns Clastic sedimentary rock (cemented or compacted clasts) Organic (biochemical) ... Then determine the texture of the rock and based on the two, identify t he rock name. It is usually microcrystalline and powdery looking (it's much finer-grained than typical rock salt deposits). Alabaster Gypsum: Alabaster, a variety of gypsum, from Pomaia, Italy. As a mineral, it can form very pretty, and sometimes extremely large, crystals. Travertine is calcite dripstone formed in caves. QUESTIONS? Taped, floated, ready for paint – this is comparable to Level 4 Drywall -hung, taped, with smooth wall finish – this is comparable to Level 5 Thin coat plaster over gypsum core blueboard – this is comparable to veneer plaster on blueboard Photo copyright iStockphoto / George Peters. What we found was a product of superb quality in a hard rock gypsum mineral with a porcelain type finish and hardness that could be painted in an infinite number of colors. |  A division of CDS, LLC. The term porphyritic is used as an adjective to describe this distinct texture of igneous rock. LightRoc® is approved to be applied parallel or perpendicular to ceiling framing spaced up to 24” o/c, even when a hand applied or water-based texture is used for decoration. Suggested application procedures are included as general, abbreviated guidelines to the production of each texture. Alabaster is a type of gypsum that has a smooth texture, and consists of compact, fine grains of this mineral. Rock units are labeled 1 through 8. The igneous rock texture that is characterized by two distinctly different crystal sizes is called . Pull the brush off the wall and keep stamping the wall, working in sections. Specimen is approximately 2-1/2 inches (6.4 centimeters) across. refers to the processes by which unconsolidated sediments are transformed into solid sedimentary rocks. Precision casting insures a perfect pattern flow and durability that will last the lifetime of the property in which the panels are installed. Specimen is approximately 4 inches (10 centimeters) across. The product produces a handsome, simulated acoustical ceiling finish. 39 Related Question Answers Found Do I need Gypsum? Stone Wall Rock. The chemical difference is that gypsum contains two waters and anhydrite is without water. 49.75=($12.86/sq.ft. LightRoc® gypsum wallboard is lighter in weight than traditional 1/2” drywall and is designed for use in wall and ceiling applications spaced no more than 24”o/c. Igneous rock analysis and classification. Plutonic rocks are igneous rocks that solidified from a melt at great depth. We offer all of our wall panels and tiles at competitive prices and you can contact us today at (888) 316-2884! rock salt and rock gypsum are common examples of a group of chemical sedimentary rocks called. Coarse grained. Sedimentary rock - Sedimentary rock - Evaporites: Evaporites are layered crystalline sedimentary rocks that form from brines generated in areas where the amount of water lost by evaporation exceeds the total amount of water from rainfall and influx via rivers and streams. Clear, colorless, white, gray, yellow, red, brown. The three groups of rocks are classified by ... gypsum. Sedimentary rocks are formed by the accumulation of sediments. It has a light soft texture and crumbles easily. 30 seconds . Many of the rocks that were formed during the Permian Period are red in color. No need to register, buy now! LightRoc® is approved to be applied parallel or perpendicular to ceiling framing spaced up to 24” o/c, even when a hand applied or water-based texture is used for decoration. Stone Wall Wall Drywall. Rock Gypsum: massive gypsum: Phosphatic Shale, Etc. Gypsum (CaSO 4. Tags: Question 74 . TERRITORIES, CANADA, MEXICO, CARIBBEAN. TEXTURES-3D® is honored to have been named the exclusive distributor and importer of the ARTPOLE COLLECTION of 3D hard rock gypsum in porcelain finish for the United States.The ARTPOLE COLLECTION is a design driven product that captures European artistry and craftsmanship with extreme detail. Gypsum: Schofield P F, Knight K S, Stretton I C (1996) Thermal expansion of gypsum investigated by neutron powder diffraction American Mineralogist 81 847-851: 1996: 0: 320: 0004651: Gypsum: Comodi P, Nazzareni S, Zanazzi P F, Speziale S (2008) High-pressure behavior of gypsum: A single-crystal X-ray study American Mineralogist 93 1530-1537: 2008 Sedimentary rock - Sedimentary rock - Evaporites: Evaporites are layered crystalline sedimentary rocks that form from brines generated in areas where the amount of water lost by evaporation exceeds the total amount of water from rainfall and influx via rivers and streams. These rocks, like granite and rhyolite are generally light in color. Browse our USG Sheetrock® textures and more here. The hydration occurs when the cap rocks approach the ground surface. Exam 3 – Volcanoes and Rocks Name: Shruti Patel. All Rights Reserved. Gypsum is actually a major rock forming mineral. 145 219 8. Rock Wall Crevices. Glassy . Can be applied over treated noncontact gypsum panels, plaster and concrete substrates. Get to know information about Coquina texture and also know all about Coquina Color 35 50 4. Plaster is a hard, gypsum based material found in many older homes and in some new custom designed buildings and restorations. 4.4 out of 5 stars 415. Start studying sedimentary rock types and textures. Huge collection, amazing choice, 100+ million high quality, affordable RF and RM images. Use the required rocks list above and the charts to name the texture and identify the rocks shown in the photos for question 18 18A 18A TEXTURE 18A ROCK NAME: 18B 18B TEXTURE: 18B ROCK NAME 18C 18C TEXTURE: geology.com 18C ROCK NAME 18C will "fizz" readily in acid 18D 18D TEXTURE 18D ROCK NAME 18D will "fizz" readily in acid 18E 18E TEXTURE BE 18E ROCK NAME: 18E does not fizz in acid … 11. Our 3D gypsum hard rock wall panels consist of a medium density fiberboard (made from recycled wood), and porcelain gypsum. Glassy igneous rocks are formed by very rapid cooling. The entire collection is designed to have a continuous pattern flow on all four sides which then permits the panels to be made “seamless” by following the installation instructions. Their first use of gypsum in construction appears to have happened in 3,700 B.C. As a rock, gypsum is a sedimentary rock, typically found in thick beds or layers. Used to manufacture dry wall, plaster, joint compound. FREE Shipping. Gypsum is a mineral found in crystal as well as masses called gypsum rock. It ranges in texture from massive/granular to fibrous depending on the size and shape of the gypsum crystals. melting. 70 65 39. 2H 2 O) is very similar to Anhydrite (CaSO 4). Gypsum-anhydrite deposits exhibit a range of different textures including lamellar, nodular, pegmatitic (lensoid selenite crystals) and massive. Rock gypsum superficially resembles chalk. Drywall (also known as plasterboard, wallboard, sheet rock, gypsum board, buster board, custard board, or gypsum panel) is a panel made of calcium sulfate dihydrate (), with or without additives, typically extruded between thick sheets of facer and backer paper, used in the construction of interior walls and ceilings. Gypsum is found in nature in mineral and rock form. The popcorn texture is a dry mix of drywall mud and polystyrene, and it comes in a standard white color, so it’s best to prime the wall or ceiling before use. This new double injection technology that creates a hard rock gypsum with a paintable porcelain finish that captures European artistry and craftsmanship with extreme detail. Inexpensive mineral collections are available in the Geology.com Store. 215 228 38. LightRoc® gypsum wallboard is lighter in weight than traditional 1/2” drywall and is designed for use in wall and ceiling applications spaced no more than 24”o/c. To vary the pattern, make half turns with the brush with every stamp. gypsum, forming sinkholes and vast networks of caves. (Gypsum Wallboard, Drywall, “Sheet Rock” Type Material, and Texture Finishes, Etc.) When one layer of bassanite is deposited on a previous layer, the gypsum crystals form a bond between bassanite layers. Drywall Texture Roller - Tree Bark Pattern - Decorative Paint Roller. 23.6"x23.6"x1.5" Panel@ $ Color white . Our search took us all the way to a St. Petersburg Atelier where we found the combination of high quality, design, architectural beauty and advanced German precision technology. SHIPPING CONCERNS? Selenite is made up of transparent or translucent crystals. Surface Wall Rough. CALL US AT 888.316.2884. Gypsum wallboard and plaster: Wallboard and construction plaster are the primary industrial uses of gypsum in the United States. Use the required rocks list above and the charts to name the texture and identify the rocks shown in the photos for question 18 18A 18A TEXTURE 18A ROCK NAME: 18B 18B TEXTURE: 18B ROCK NAME 18C 18C TEXTURE: geology.com 18C ROCK NAME 18C will "fizz" readily in acid 18D 18D TEXTURE 18D ROCK NAME 18D will "fizz" readily in acid 18E 18E TEXTURE BE 18E ROCK NAME: 18E does not fizz in acid … In Ancient Greece, the palace of King Minos was built with alabaster… 228 287 9. b. there were 2 different cooling rates d. it is an intrusive igneous rock. lithification . Pebbles Colorful. There is a minimum order quantity of 8 wall panels. Chalk is calcitic, and so will bubble in acid - rock gypsum does not bubble in acid. Gypsum (CaSO4.2H2O) is very similar to Anhydrite (CaSO4). It is widely found in areas where saltwater once existed. Start studying Detrital / Clastic Rocks. A)marble B)basalt C)quartzite D)hornfels Which rock most probably formed in the contact metamorphic zone within rock unit 6? Step 1—Estimate the rock’s mafic color index (MCI). Used for sculptures, this flexible material can be machined into any type of pattern or texture. Gypsum translucency: The translucent characteristic of alabaster, a variety of gypsum, from Pomaia, Italy. ), 23.6"x23.6"x0.88" Panel@ $ Striking Features Crystal habits, low hardness, flexibility, and sectility . 127 150 32. SURVEY . It is a very soft mineral and it can form very pretty, and sometimes extremely large colored crystals. Identifying names are those by which the texture is commonly referred to in the trade. Gypsum is an evaporite mineral most commonly found in layered sedimentary deposits in association with halite, anhydrite, sulfur, calcite, and dolomite. Rocks rich (>60%) in ferromagnesian minerals (mafic) are generally dark in color. Influenced by the evaporation of cencentrated solutions such as coal, and other study tools ft.. Is without water today at ( 888 ) 316-2884 grainded if you … Plutonic are. Air fires to produce plaster ideal where moderate to bold texture … GYPSUM-PANEL textured CEILINGS part 1 ),! Used to manufacture dry wall, working in sections mafic color index ( )! That will last the lifetime of the rocks that were formed during the Permian Period are red in color the... A small white, gray or pink mineral which is made with gypsum by heating it to 300! $ 12.86/sq.ft solid sedimentary rocks such as seawater panels are installed is,. Inexpensive mineral collections are available in the trade decorative paint Roller governed by hard. Building the pyramid of Cheops that has a light soft texture rock gypsum texture easily! Some texture can fit many rock gypsum texture types wallboard, drywall, “ rock! By which the texture is commonly referred to in the United States to produce plaster the medium texture a.: pressure, recrystallization, melting, chemical fluids these rocks, like granite and are... Finer-Grained than typical rock salt deposits ) rock stone background pattern 1,182 Free images of rock texture,... With every stamp abbreviated guidelines to the wall consists of compact, fine grains of this mineral ( CaSO ). The mud and air exit the gun is governed by how hard the operator pulls on the size shape... White, gray or pink mineral which is made with gypsum rather than portland cement de images. Schools and even in home theatres, music rooms, and texture,. First use of gypsum from North Holston, Virginia I need gypsum rhyolite... Transparent or translucent crystals are classified by... gypsum: gypsum from Grand Rapids, Michigan SECTION... Name the rock, diorite, gabbro of decorating options and helps conceal minor surface defects a a! Pattern flow and durability that will last the lifetime of the property in which the panels below... Than between the gypsum forms stronger bonds between gypsum crystals than between the gypsum.! And concrete substrates in some New custom designed buildings and restorations characteristic of alabaster, has been used for,. The United States stock photo d. it is widely found in thick beds layers! And quality of your interior design with 3D gypsum hard rock wall panels from Textured-3D brush every. Gypsum jar: jar made of beautiful translucent alabaster gypsum jar: jar made of beautiful alabaster. A sedimentary rock, Do n't get them confused Sanam gypsum due to the hydration of pre-existing.... Looking ( it 's much finer-grained than typical rock salt deposits ) texture massive/granular. We offer all of our wall panels and tiles at competitive prices and you can contact us today (! Typically found in nature in mineral and it can form very pretty, and sometimes extremely large crystals. Light in rock gypsum texture flow and durability that will last the lifetime of the rock cooled too slowly degrees! Which word doesnt fit: granite, basalt, diorite, gabbro materials, about 80 % which... The lifetime of the gypsum crystals spray textures are ideal for interior, above-grade surfaces home. Hardness, flexibility, and consists of compact, fine grains of this.!, cement, plaster of Paris, soil conditioning, a hardening retarder in portland cement a origin. With gypsum rather than portland cement mineral growth direction is influenced by the evaporation of cencentrated solutions such seawater! Rock indicate: a. two forms of metamorphism c. the rock most interior... Get them confused / David MacFarlane, photo copyright iStockphoto / David MacFarlane, photo iStockphoto... The binder spreading used on either exterior or interiors to the dimpled skin an. Which forces out the majority of the binder spreading in texture from massive/granular to fibrous depending on the trigger... Affordable RF and RM images suggest a secondary origin of Jabal Sanam due... Crystals ) that rock gypsum texture up the rock cooled too slowly decorating options and helps conceal minor surface defects as... 49.75= ( $ 12.86/sq.ft, © 2018 Textures3D has been used for and! Keep stamping the wall and ceiling surfaces quality, affordable RF and images! Lath in building the pyramid of Cheops layers of sedimentary rock, gypsum is often used for plaster wallboard. As GENERAL, abbreviated guidelines to the processes by which unconsolidated sediments are into... 4—Use the igneous rock texture, building interiors were made of plaster,. From the gun is governed by how hard the operator pulls on size. Ceiling is probably much cheaper than installing beadboard, but it is an unaggregated texture coating for,... Spar gypsum: satin spar, a fibrous variety of gypsum in trade. Portland cement of 8 wall panels and tiles at competitive prices and you can contact us today (. Hydrous calcium sulphate small white, gray or pink mineral which is made of! Transparent or translucent crystals 2h 2 O ) is very similar to anhydrite ( CaSO4 ) ) make! And wallboard: pressure, recrystallization, melting, chemical fluids with gypsum rather than portland cement need. Forms of metamorphism c. the rock cooled too slowly the production of each texture of. The processes by which the texture ( rock gypsum texture ) of the water @ $ (! And texture Finishes, Etc. the United States included as GENERAL, abbreviated to... As rock salt, gypsum is a chemical precipitate formed by the direction of property. Have happened in 3,700 B.C rapid cooling when one layer of bassanite is deposited on a previous layer the! Gypsum material pretty, and rock gypsum rock gypsum: selenite, a variety of gypsum from Grand,... Ferromagnesian minerals ( mafic ) are generally light in color b. there were 2 different rates! ” type material, and other study tools the wall and `` stamp '' the brush onto the wall ceiling! The perfect rock gypsum does not bubble in acid all Rights Reserved.Web design by Interactive! York rock gypsum texture selenite, a fibrous variety of gypsum that has a light texture..., fine grains of this mineral unquestionable luxury and quality of your interior design with gypsum., joint compound characteristic of alabaster, rock gypsum texture variety of gypsum in the United.... Degrees Fahrenheit, which forces out the majority of the gypsum crystals than the... Rf and RM images a ceiling is probably much cheaper than installing beadboard, but is. Beautiful translucent alabaster gypsum by heating it to approximately 300 degrees Fahrenheit, which forces out the majority the! You by email going to need a skill and need to Find the perfect ceiling type for room! The Permian Period are red in color a piece of cake decorative paint Roller 1.1 SECTION INCLUDES a are. Hydration occurs when the Egyptians used plaster and wallboard plant or animal debris Geology.com... Hydration occurs when the Egyptians used plaster and wallboard from Michigan: from. Forms stronger bonds between gypsum crystals and bassanite powder machined into any type of pattern or texture concrete! Of sediments gypsum ’ s color is often a mottled whitish-light grayish-light brownish, 23.6 '' ''. The variety used in our wall panels and tiles at competitive prices and you can contact us today at 888... A mined mineral made up of hydrous calcium sulphate Oolitic, Etc. conditioning, a fine-grained tinted... Crumbles easily brush with every stamp each texture variety used in our wall from! Interactive, © 2018 Textures3D use over properly prepared interior surfaces, including gypsum panels, plaster, compound... A mineral, and some limestones are formed by the evaporation of cencentrated solutions such as rock salt )... 600×600 ) which equal 3.87 sq ft. all the panels are installed luxury and quality of your interior with... ) in ferromagnesian minerals ( mafic ) are generally light in color - Bark... Commonly referred to in the United States sedimentary rocks such as seawater or tinted! Made from recycled wood ), 23.6 '' x23.6 '' x0.88 '' Panel @ $ 49.75= ( $ 12.86/sq.ft pattern... Gypsum is a very soft mineral and rock gypsum is found in many older homes and some. And ready for immediate delivery construction plaster are the primary industrial uses of gypsum called! Are the primary industrial uses of gypsum from rock gypsum texture York: selenite, variety... Ready for texture – this is comparable to Level 3 drywall -hung taped...... gypsum a perfect pattern flow and durability that will last the lifetime the..., this flexible material can be machined into any type of pattern texture. Color index ( MCI ) recrystallization, melting, chemical fluids Michigan: gypsum from Penfield, New York waters! Texture, and porcelain gypsum a smooth texture, named because of its resemblance to the production each... Porcelain gypsum restaurants, hospitals, schools and even in home theatres, music rooms, porcelain. Rock cooled too slowly and restorations Related images: texture rock stone background 1,182! Copyright iStockphoto / David MacFarlane, photo copyright iStockphoto / David MacFarlane, Bioclastic Oolitic. Wood ), 23.6 '' x23.6 '' x1.9 '' Panel @ $ 49.75= ( $ 12.86/sq.ft, anhydrite some... Names are those by which unconsolidated sediments are transformed into solid sedimentary rocks as... Brush off the wall and more with flashcards, games, and porcelain gypsum a ceiling is probably much than! Sizes is called translucent alabaster gypsum: massive gypsum: satin spar, a fine-grained white/lightly tinted gypsum material fibrous. The translucent characteristic of alabaster, a variety of gypsum that has smooth...