Sphalerite cleavage

Sphalerite gem hardness ranks quite low. Combined with its brittleness and perfect cleavage, sphalerite is a difficult gem to cut. Therefore, it's more common as a raw, collector's specimen. Expert gem cutters who attempt it usually pick faceted cuts for displaying brilliance, like trillions, rounds, and cushions.

Sphalerite is one of the very few minerals that has a total of six directions of cleavage. If all of them were to be perfectly cleaved on a single crystal it would form a rhombic …Hemimorphite is a zinc silicate mineral with a chemical composition of Zn 4 Si 2 O 7 (OH) 2 *H 2 O. It contains up to 54% zinc by weight and is a minor ore of zinc. Hemimorphite is a common secondary mineral found in the weathered rocks above and around zinc deposits. Most hemimorphite is white, gray, colorless, or brown.Cleavage: {110} Distinct : Color: Tin white, Light steel gray. Density: 6.07 : Diaphaneity: Opaque : Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals. Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form. Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline). Habit:Physical Properties of Galena. Galena is a very soft mineral, registering only 2.5 on the Moh's hardness scale. And even worse, galena has perfect cleavage and brittle tenacity. This means that specimens are very easily damaged by just a tiny chip or bruise. When dropped or smashed, galena easily splits into tiny cubes.SPHALERITE - ZnS Sphalerite (old names: “blende ”, “zinc blende”) is a common sulfide and the main ore of Zn. May constitute a Cd ore. Sphalerite is usually massive. Crystals are rare, tetrahedral and dodecahedral, typically very complex and distorted (conical and curved faces); can look like octahedrons, reach 30 cm. Twins are common,To determine if your Sphalerite is real, you can look for its characteristic brown or orange-yellow color, as well as its high luster and perfect cleavage. Sphalerite forms dark, …Sphalerite can be difficult to identify because of its variable luster, color, abundant but obscured cleavage and crystal habits. So difficult was sphalerite for miners to distinguish from more valuable minerals such as galena, acanthite and tetrahedrite, that they named it sphalerite which is Greek for treacherous rock and blende is German for ...Among the sulfur-bearing minerals, few have the color, luster, streak and cleavage of sphalerite. Galena, for which it is most frequently mistaken, is always ...

14. Provide an economic use for each mineral listed below. Galena: Hematite: Graphite: Sphalerite: Gypsum: Calcite: 10. What term is used to describe the tenacity of muscovite? 11. Use the mineral identification key (see Figure 24) to identify a mineral that is nonmetallic, dark colored, harder than glass, lacking cleavage, and green in color. Fire was pyrite’s most prominent gift to human society. Sparks are created when pyrite is struck against metal or a hard surface and this was one of the earliest methods humans discovered to create flame. Pyrite’s name comes from the Greek phrase, ‘pyrite lithos,’ which means ‘stone which strikes fire.’. Its brilliant metallic ... Sphalerite. Chemical composition: ZnS. Color and Luster: color varies from yellow to light to dark brown, red-brown, red, black, and colorless, and is less commonly light blue or green. It has a resinous to adamantine luster. Hardness: 3.5 to 4. Cleavage: 1 perfect. Specific gravity: 3.9 to 4.1. Crystal system: Isometric crystal systemCalcite CaCO 3. Origin of Name From the Latin word calx, meaning “burnt lime.”. Figure 14.361: Calcite cleavage fragments Figure 14.362: Calcite cleavage fragments. Hand Specimen Identification Calcite is identified by its hardness of 3, rhombohedral cleavage, and effervescence in cold dilute HCl. It may be confused with dolomite or aragonite.Dolomite …Sphalerite crystallizes in the isometric crystal system and possesses perfect dodecahedral cleavage. In the crystal structure, zinc and sulfur atoms are tetrahedrally coordinated. This structure is closely related to that of diamond. Two other minerals, wurtzite and matraite, are polymorphs of sphalerite. Diamond is distinguished by its occurrences, hardness, octahedral cleavage and sometimes octahedral shape, and luster. Diamonds are mined from alluvial (placer) deposits and from kimberlite pipes. Figure 14.240 shows alluvial diamonds, and Figure 14.241 shows a large diamond in kimberlite. Physical Properties

Chalcopyrite is an important ore of copper found in a wide range of hydrothermal environments. It is often associated with sphalerite and galena. It oxidizes to form copper minerals such as malachite, azurite, cuprite and tenorite. Copper liberated from the breakdown of chalcopyrite may accumulate in secondary supergene enrichment zones, forming chalcocite, bornite, covellite and similar ... Sphalerite cleavage surface dissolution in acidic (HC1) and oxygen-saturated solutions was investigated by liquid-cell Atomic Force Microscopy (AFM). The sphalerite surface was cleaved in the laboratory and then mounted in the liquid cell at 298 K with a fast continuous renewal of the interacting solution. AFM data indicate that unreacted (110 ...Sphalerite, for the same reason, is derived from a Greek word meaning treacherous. Sphalerite is the most important ore of zinc. The chief uses for metallic zinc are in galvanizing iron, making brass, (an alloy of copper and zinc), in electric batteries, and as sheet zinc.14. Provide an economic use for each mineral listed below. Galena: Hematite: Graphite: Sphalerite: Gypsum: Calcite: 10. What term is used to describe the tenacity of muscovite? 11. Use the mineral identification key (see Figure 24) to identify a mineral that is nonmetallic, dark colored, harder than glass, lacking cleavage, and green in color.

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The other specimen 8c is also quartz It is described as crystalline and consists from GEOL 1403 at Blinn CollegeMar 12, 2022 · Sphalerite gem hardness ranks quite low. Combined with its brittleness and perfect cleavage, sphalerite is a difficult gem to cut. Therefore, it’s more common as a raw, collector’s specimen. Expert gem cutters who attempt it usually pick faceted cuts for displaying brilliance, like trillions, rounds, and cushions. Sphalerite deposits are found in many geologic regions on Earth. Specifically, found within skarns, hydrothermal deposits, volcanogenic massive sulfide deposits ...Aug 28, 2022 · Some calcite specimens contain euhedral crystals, but many are rhombohedral cleavage fragments like those in Figures 14.361 and 14.362. The photo in Figure 14.361 shows calcite with its most common whitish color. The photo in Figure 14.362 shows (less common) blue calcite cleavage fragments. Other colors too, are possible. Dodecahedral cleavage: some high symmetry minerals may have six cleavage planes that intersect in space separating small dodecahedrons (e.g. sphalerite). Pinacoidal …

Black Jack. Blende. Zinc Blende. VARIETIES. Cleiophane. - Transparent, lightly colored variety of Sphalerite. Marmatite. - Opaque, metallic luster ed, ironrich variety of …Gemstone Cleavage Chart. One of the characteristics of crystals is that they have cleavage. Cleavage is the tendency of a crystal to break cleanly along distinct planes. Since most gemstones are crystals, cleavage is an issue that gem buyers as well as jewelers and gem cutters need to take into account. Minerals can have from one to five ...2 Haz 2022 ... Cleavage is perfect in six directions to from dodecahedron. Fracture = conchoidal. Streak is yellow or light brown. Luster = adamantine; Some ...Calcite has perfect cleavage in three directions to produce rhombohedra. (Cleavage in aragonite is generally less well developed.) Hardness. 3 (down to 2.5 on some surfaces) – easily scratched by a metal nail, but too hard to be scratched by a fingernail. Aragonite is slightly harder, from 3.5 to 4. Specific Gravity. Halite -cubic cleavage -tastes salty; calcite -reacts to acid -good cleavage in three directions; Olivine -sandy or sugary texture; Sphalerite -cleavage in six directions; Pumice -igneous -light to dark grey -single background color with few to no observable minerals -contains vesicles -aphanitic vesicular textureAverage surface energies of the sphalerite and wurtzite phases of zinc sulfide (ZnS) were calculated to be 0.86 and 0.57 J/m2, respectively, using results from dynamics simulations of free faces ...PE Sphalerite = 35.10 barns/electron U=PE Sphalerite x rElectron Density= 135.25 barns/cc. Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units) Sphalerite is Not RadioactiveSphalerite: Yellow to black submetallic, vitreous, or resinous crystals with 6 cleavage faces; can form dodecahedrons; smells like rotten eggs when scratched, powdered, or treated with acid. Softer than glass (H=3.5-4).Sphalerite. Type: Mineral: Luster: Nonmetallic Resinous: Hardness: 3.5 – 4 > Fingernail but < Glass: Cleavage: Yes 6 perfect cleavages: Streak: Pale Yellow: Color: Yellow Brown to Black: Miscellaneous: Powdered streak smells like rotten egg: East Carolina University Department of Geological SciencesVHN = 16–19 (perpendicularly to cleavage), 21–28 (parallel to cleavage). ... Sphalerite (grey) with chalcopyrite (yellow), galena (white) and pyrrhotite ...

Jul 1, 2017 · Miners call sphalerite "jack," "blackjack," or "zinc blende." Its impurities of gallium, indium and cadmium make sphalerite a major ore of those metals. Sphalerite has some interesting properties. It has excellent dodecahedral cleavage, which means that with careful hammer work you can chip it into nice 12-sided pieces.

War I, barite was mined along with fluorite and sphalerite in Jessamine, Woodford, and Fayette Counties. Limited bar ite mining was attempt ed during the 1960s in Lincoln and Boyle Counties. Commercial barite was recovered as a byproduct of fluorspar production in western Kentucky during World War II and the 1960s. CALAMINE (HEMIMORPHITE )Dodecahedral cleavage: some high symmetry minerals may have six cleavage planes that intersect in space separating small dodecahedrons (e.g. sphalerite). Pinacoidal cleavage : it occurs in some prismatic minerals like barite, whose planes of weakness are oblique to both the basal and prismatic planes (i.e. pinacoidal plane).Sphalerite can be difficult to identify because of its variable luster, color, abundant but obscured cleavage and crystal habits. So difficult was sphalerite for miners to distinguish from more valuable minerals such as galena, acanthite and tetrahedrite, that they named it sphalerite which is Greek for treacherous rock and blende is German for ...Sphalerite is zinc sulfide, an ore of zinc. The name comes from the Greek "sphaleros," meaning treacherous, in reference to how easy it is to mistake the darker varieties for galena, a lead ore. ... (3.5-4.0 Mohs scale) and perfect cleavage, sphalerite is a fragile gemstone that is not commonly used in jewelry. However, it shows great ...Average surface energies of the sphalerite and wurtzite phases of zinc sulfide (ZnS) were calculated to be 0.86 and 0.57 J/m2, respectively, using results from dynamics simulations of free faces ...Dodecahedral cleavage: some high symmetry minerals may have six cleavage planes that intersect in space separating small dodecahedrons (e.g. sphalerite). Pinacoidal cleavage: it occurs in some prismatic minerals like barite, whose planes of weakness are oblique to both the basal and prismatic planes (i.e. pinacoidal plane).Dolomite is a very common mineral, and is known for its saddle-shaped curved crystal aggregates. A unique, isolated Dolomite occurrence in Eugui, Spain has provided colorless transparent crystals that resemble the Iceland Spar variety of Calcite.The occurrence of Kolwezi, in the Congo, has produced some fascinating, cobalt-rich specimens that are a …All members of the calcite group crystallize in the trigonal system, and have perfect rhombohedral cleavage. Siderite is easily altered to iron oxides. A brown Goethite replacement of Siderite is common. Limonite, an amorphous mineral, is commonly found in rhombohedral crystals, as it frequently pseudomorphs after Siderite.

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Oily wastewater from solvent extraction is hard to be treated due to a large number of organic pollutants and high salt content. Here, we found a photocatalyst (natural sphalerite (NS), (Zn, Fe)S)) with great application potential for treating oily wastewater of solvent extraction, and studied its application in removal organics from actual solvent …Cleavage: Sphalerite is known to exhibit perfect cleavage in six separate directions, which means that the mineral can be easily broken along certain planes. This cleavage is a result of the unique arrangement of atoms in the mineral’s crystal structure, with tightly bound atomic bonds in some directions and weaker bonds in others.Sphalerite (which is also known as Blende), is an important ore of zinc and can make a rather attractive cabinet specimen as well. It can have excellent luster and associates with many beautifully colored minerals making it one of the best enhancers of many fine mineral specimens. ... Cleavage is perfect in six directions forming dodecahedrons ...Minerals that have cleavage can also fracture along surfaces that are not parallel to their cleavage planes (Figure 2.3.6). Figure 2.3.5: Common types of cleavage, and conchoidal fracture (top left), with illustrations to indicate cleavage directions and angles between cleavage planes. Figure 2.3.6: Cleavage and fracture in potassium feldspar. Cleavage can also be described by general forms names, for example if the mineral breaks into rectangular shaped pieces it is said to have cubic cleavage (3 cleavage directions), if it breaks into prismatic shapes, it is said to have prismatic cleavage (2 cleavage dir ections), or if it breaks along basal pinacoids( 1 cleavage direction) it is said to have pinacoidal …A superb Sphalerite gemstone from Spain, the source of the finest specimens of this popular collectors gem. Also known as 'Zinc Blende' this sulphide ...Cleavage: Perfect in 6 directions; easily developed: Fracture: Concoidal to uneven: Hardness: 3.5-4.0: Optic nature: ... Adamantine to Subadamantine: Figure \(\PageIndex{1}\): Round Brilliant Sphalerite Photo courtesy of Rick Martin, Art Cut Gems. 16.65: Sphalerite is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated ...Characteristics: Crystal System Color Habit Cleavage Cubic hexatetrahedral. Gra y -black, yellow, red, tan, brown, black. Green (Co ) to almost colorless. Massive, cleavable …Sphalerite can be difficult to identify because of its variable luster, color, abundant but obscured cleavage and crystal habits. So difficult was sphalerite for miners to distinguish from more valuable minerals such as galena, acanthite and tetrahedrite, that they named it sphalerite which is Greek for treacherous rock and blende is German for ... Physical properties. Sphalerite possesses perfect dodecahedral cleavage, having six cleavage planes. [10] [18] In pure form, it is a semiconductor, but transitions to a … ….

The Mineral galena. Galena is the most common mineral containing lead, and has been well-known throughout the centuries. It is often well crystallized and forms in many interesting and distinct crystal shapes. Some cubic crystals have their edges cut by the partial octahedral growth, some octahedral crystals have their points flattened by cubic ...Sphalerite (which is also known as Blende), is an important ore of zinc and can make a rather attractive cabinet specimen as well. It can have excellent luster and associates with many beautifully colored minerals making it one of the best enhancers of many fine mineral specimens. ... Cleavage is perfect in six directions forming dodecahedrons ...Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. Habit: Acicular - Occurs as needle-like crystals. Habit: Massive - Uniformly indistinguishable crystals forming large masses. Hardness: 3-3.5 - Calcite-Copper Penny : Luminescence: Non-fluorescent. Luster: Metallic : Magnetism: Magnetic after heating ...Sphalerite, for the same reason, is derived from a Greek word meaning treacherous. Sphalerite is the most important ore of zinc. The chief uses for metallic zinc are in galvanizing iron, making brass, (an alloy of copper and zinc), in electric batteries, and as sheet zinc. Mineral Properties. In order to use this Key and the test kit described above, you need to understand some basic properties of minerals. The most important are: luster, streak, hardness, and cleavage. It is also good to know a bit about such things as specific gravity, fusibility, mineral "habits", and the types of mineral "environments ...Sphalerite mineral is in group of Sulfide mineral that is formula ( (Zn, Fe)S).It is the principal ore of zinc. Pure sphalerite is colorless and rare. Normally, iron is present, causing the color to vary from pale greenish yellow to brown and black with increasing iron content. When iron content is high it is an opaque black variety, marmatite.Sphalerite Sphalerite is the major ore of zinc. It is a sulphide mineral and exhibits a wide range of physical properties, such as colour, transparency, streak and lustre, because many elements can substitute for Zn in its crystal structure. Iron is the principle substituent, but cadmium, gallium and iridium can also substitute to economic volumes making …Sphalerite (sometimes spelled sphaelerite) (which is also known as Blende), is an important ore of zinc and can make a rather attractive cabinet specimen as ... Sphalerite cleavage, The optimized sphalerite unit cell was later used to cleave the (110) sphalerite plane which is its perfect cleavage plane and has been used as the principle sphalerite cleavage plane by different ..., Diamond is distinguished by its occurrences, hardness, octahedral cleavage and sometimes octahedral shape, and luster. Diamonds are mined from alluvial (placer) deposits and from kimberlite pipes. Figure 14.240 shows alluvial diamonds, and Figure 14.241 shows a large diamond in kimberlite. Physical Properties, 2 Haz 2022 ... Cleavage is perfect in six directions to from dodecahedron. Fracture = conchoidal. Streak is yellow or light brown. Luster = adamantine; Some ..., 17 Ara 2019 ... ... sphalerite (zinc sulfide, ZnS) led to the spatial redistribution of ... e of S2 cleavage. C: EDS Ge map acquired. simultaneously to EBSD ..., Calcite has perfect cleavage in three directions to produce rhombohedra. (Cleavage in aragonite is generally less well developed.) Hardness. 3 (down to 2.5 on some surfaces) – easily scratched by a metal nail, but too hard to be scratched by a fingernail. Aragonite is slightly harder, from 3.5 to 4. Specific Gravity. , The Mineral galena. Galena is the most common mineral containing lead, and has been well-known throughout the centuries. It is often well crystallized and forms in many interesting and distinct crystal shapes. Some cubic crystals have their edges cut by the partial octahedral growth, some octahedral crystals have their points flattened by cubic ..., Sphalerite is a stone of earth and fire energy; it can be an excellent stone for stimulating passion, growing confidence and sparking creativity. This is especially effective when paired with a Carnelian, or any fiery crystal. Romantically, Thulite or Zoisite is a nice compliment. Chakra: The three lower chakras, primarily the root chakra., Sphalerite, also known as blende or zinc blende, is the major ore of zinc. When pure (with little or no iron) it forms clear to white crystals (known as Cleiophane ). Yellow to orange sphalerite is often called "golden sphalerite." Red shades of sphalerite are known as Ruby Blende or Ruby Jack. As iron content increases, sphalerite forms dark ... , Pyrrhotite. Comments: Lustrous sharp crystals of pyrrhotite to 3.5 cm in size with minor sphalerite and chalcopyrite. Location: Nikolaevskiy mine, Dal'negors, Primorskiy Kray, Russia., Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula (Zn,Fe)S. It is the most important ore of zinc.Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfides), calcite ..., Calcite has perfect cleavage in three directions to produce rhombohedra. (Cleavage in aragonite is generally less well developed.) Hardness. 3 (down to 2.5 on some surfaces) – easily scratched by a metal nail, but too hard to be scratched by a fingernail. Aragonite is slightly harder, from 3.5 to 4. Specific Gravity., Sphalerite. Luster: metallic or Adamentine (gem like) Hardness: 3.5-4 Cleavage: dodecahedral Streak: light yellow-brown Smells like sulfur. Pyrite. Luster: ..., first of all diamond has perfect cleavage in three directions (similar to sphalerite). Cleavage surfaces are well visible on any waterworn diamond grain. ... no traces of cleavage. Secondly, diamonds has strong bluish-green responce under X-rays. 14th Oct 2016 02:19 UTC Brett., Dolomite is a common rock-forming mineral. It is a calcium magnesium carbonate with a chemical composition of CaMg (CO 3) 2. It is the primary component of the sedimentary rock known as dolostone and the metamorphic rock known as dolomitic marble. Limestone that contains some dolomite is known as dolomitic limestone., Sphalerite can be difficult to identify because of its variable luster, color, abundant but obscured cleavage and crystal habits. So difficult was sphalerite for miners to distinguish from more valuable minerals such as galena, acanthite and tetrahedrite, that they named it sphalerite which is Greek for treacherous rock and blende is German for ... , Sphalerite keeps the energy flowing so that you can continue to pursue the things that make you happy. Its meaning encourages you to find your true calling and precisely determine what you're meant to do on this planet. Sphalerite Uses. Sphalerite is just as versatile as many other popular healing crystals. There are many ways to use it in ..., 2 Haz 2022 ... Cleavage is perfect in six directions to from dodecahedron. Fracture = conchoidal. Streak is yellow or light brown. Luster = adamantine; Some ..., While most graphite is formed through the metamorphism of organic material in rocks, it also occurs in igneous rocks and is found as nodules inside of iron meteorites. Chemical composition - C. Hardness - 1-2. Specific gravity - 2.2. Transparency - Opaque. Colour - Silver-black. Streak - Shiny black. Lustre - Metallic to earthy., Cleavage. Cleavage is a mineral’s tendency to break along planes of weakness within its atomic structure. The chemical bonds in muscovite, for example, are strong within the planes of the silicate sheets but weak between them, causing muscovite crystals to cleave easily into thin sheets. Some minerals, such as mica, feldspar, and fluorite,, Sphalerite. Sphalerite is an ore—a mineral of economic value—that was once mined in southeastern Kansas for its zinc content. It is also called zinc blende, blende, blackjack, and mock lead. Sphalerite crystals are usually shaped like triangular pyramids, with three sides and a base. Because it has good cleavage in six directions ..., Black Jack. Blende. Zinc Blende. VARIETIES. Cleiophane. - Transparent, lightly colored variety of Sphalerite. Marmatite. - Opaque, metallic luster ed, ironrich variety of …, Chalcopyrite is easily the most widespread copper-bearing mineral. A common mineral found in almost all sulfide deposits, chalcopyrite usually occurs in medium-temperature and high-temperature hydrothermal veins in igneous rocks or metamorphosed igneous rocks. Some economic chalcopyrite deposits form as hydrothermal fluids dissolve copper from ... , Miners call sphalerite "jack," "blackjack," or "zinc blende." Its impurities of gallium, indium and cadmium make sphalerite a major ore of those metals. Sphalerite has some interesting properties. It has excellent dodecahedral cleavage, which means that with careful hammer work you can chip it into nice 12-sided pieces., Sphalerite is often found with galena, a lead ore. · Sphalerite is a mineral, mixed with zinc and iron sulfide. · The chemical formula of Sphalerite is (Zn, Fe)S., Jul 1, 2017 · Miners call sphalerite "jack," "blackjack," or "zinc blende." Its impurities of gallium, indium and cadmium make sphalerite a major ore of those metals. Sphalerite has some interesting properties. It has excellent dodecahedral cleavage, which means that with careful hammer work you can chip it into nice 12-sided pieces. , Cleavage can also be described by general forms names, for example if the mineral breaks into rectangular shaped pieces it is said to have cubic cleavage (3 cleavage directions), if it breaks into prismatic shapes, it is said to have prismatic cleavage (2 cleavage dir ections), or if it breaks along basal pinacoids( 1 cleavage direction) it is said to have pinacoidal …, Sphalerite has dodecahedral cleavage. Intentionally, the description above was constrained to 3D crystals which eventually are (typically) described in one of 230 3D space groups. Note, there equally are seven planar space groups , and a growing body of work about 2D crystals , too., Sphalerite. Chemical composition: ZnS. Color and Luster: color varies from yellow to light to dark brown, red-brown, red, black, and colorless, and is less commonly light blue or green. It has a resinous to adamantine luster. Hardness: 3.5 to 4. Cleavage: 1 perfect. Specific gravity: 3.9 to 4.1. Crystal system: Isometric crystal system, Sphalerite 2.5 Gray 3 cleavage planes at 90° Silvery gray, very high specific gravity Metallic Galena 1 to 2 Gray to black Poorly defined cleavage in one direction Dark gray to black, marks paper Metallic to dull or greasy Graphite 7 No streak Conchoidal or irregular fracture Colorless, white, or other colors, transparent to translucent , Chalcopyrite Group. Chalcopyrite-Eskebornite Series. A major ore of copper. Common in sulfide veins and disseminated in igneous rocks. Weathering may lead to the formation of malachite, azurite, brochantite, langite and numerous other secondary copper minerals. A Zn-rich variety is known from Atlantis II Deep (see zincian chalcopyrite).Also, the Mid …, Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. Habit: Acicular - Occurs as needle-like crystals. Habit: Massive - Uniformly indistinguishable crystals forming large masses. Hardness: 3-3.5 - Calcite-Copper Penny : Luminescence: Non-fluorescent. Luster: Metallic : Magnetism: Magnetic after heating ..., Some calcite specimens contain euhedral crystals, but many are rhombohedral cleavage fragments like those in Figures 14.361 and 14.362. The photo in Figure 14.361 shows calcite with its most common whitish color. The photo in Figure 14.362 shows (less common) blue calcite cleavage fragments. Other colors too, are possible., Sphalerite Cleavage or Fracture. 6 planes rarely seen. Sphalerite Color. yellow, brown to black. Sphalerite Streak. white to pastel yellow. Sphalerite Luster ...