Sphalerite hardness

Jan 20, 2019 · Sphalerite is a significant zinc ore which is usually found in hydrothermal veins. It can also be found in limestones where ore bodies have been created. Although it’s too fragile for making jewelry because of its 3.5 to 4.0 rating on the hardness scale, collectors find it a magnificent crystal.

Rough Jewelry Table of Contents General Information Sphalerite Colors Alternate Names Countries of Origin Care Related Videos Sphalerite makes an excellent collector's stone, but it is too soft for jewelry. It is difficult to cut and polish due to perfect cleavage in six directions.27 Nis 2021 ... Hardness of Stone. As mentioned above, one of the physical properties of stone is its hardness. In previous blogs, I have briefly mentioned ...Study with Quizlet and memorize flashcards containing terms like Name the physical property (hardness, color, streak, etc.) described by each of the following statements., What term is used to describe the shape of a mineral that has three directions of cleavage that intersect at 90-degree angles?, Describe the cleavage of the minerals listed below. …Hardness: 3½ - 4 Specific Gravity: 3.9 - 4.1 Crystal System: Isometric Member of: Sphalerite Group Name: Originally called blende in 1546 by Georgius Agricola (Georg Bauer). Known by a variety of chemical-based names subsequent to Agricola and before Glocker, including "zincum".Sphalerite . Hardness: 3.4-4 Metallic Dark 6 directions of cleavage Streak: white - pale yellow. Chalcopyrite . Hardness: 3.5-5 Metallic Dark - a dark fools gold ... Hardness: 3 Non-Metallic Cloudy, white, looks like you could peel off a piece *reacts to acid* 3 directions not @ 90° (rhombehedral) Streak: nothing .The hardness varies between 5.5 and 6.0 in Mohs scale. Figure 1.31. Arsenopyrite is a hard metallic iron arsenic sulfide with steel gray to silver-white color, and the major source of arsenic. ... galena, and sphalerite. Oxidation of arsenopyrite led to the formation of scorodite on the surface.Streak brownish yellow to orange-yellow. Brittle. Sphalerite (metallic) Submetallic to resinous luster. Color yellow to yellow-brown to dark brown. Hardness=3.5-4. Perfect vleavage in six directions (dodecahedral). Brown, light yellow, to white streak. Cleavage faces common, twinning common.Hardness: 2.5 Color: muscovite - colourless/silvery white/light green Biotite- brown to black (from Mg and Fe) ... Streak: Black (Note* streak differs from Fe-Rich sphalerite) Hardness: 6-6.5 (about same as streak plate) Color: dark grey-high specific gravity-5.2-MAGNETIC. Hematite (ore of iron) Lustre: Dull (some are submetallic)

Mineral Species: Sphalerite. Mineral Group: Sulphides. Chemical Formula: ZnS. Hardness: 3.5-4. Crystal System: Isometric. Colour: Yellow, orange, light to dark brown, red-brown to black. Typical Appearance: Usually massive crystalline or as individual euhedral crystals in a wide variety of forms and associations. When it comes to protecting your data, wiping a hard drive clean is one of the most important steps you can take. Whether you’re getting rid of an old computer or just want to make sure your data is secure, wiping a hard drive clean can hel...Sphalerite. HARDNESS: 3.5-4 PROPERTIES: Smells like rotten eggs when scratched CHEM FORM: ZnS COLOR: silvery yellow-red, black. Corundum. HARDNESS: 9 PROPERTIES: hexagon prisms with flat striated ends CHEM FORM: AI2O3 COLOR: Can be any color. Different Hardnesses. Fingernail - 2.5 Penny - 3 Glass - 5.5Mustafa Özer. This paper reports the results of flotation tests conducted with a copper-lead-zinc sulphide ore. The major sulphide minerals in the ore are chalcopyrite, galena, sphalerite ...Chalcopyrite (/ ˌ k æ l k ə ˈ p aɪ ˌ r aɪ t,-k oʊ-/ KAL-kə-PY-ryte, -⁠koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS 2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale.Its streak is diagnostic as green-tinged black.. …When it comes to protecting your data, wiping a hard drive clean is one of the most effective ways to ensure your information remains secure. With the increasing number of cyber threats, it’s important to take the necessary steps to protect...

Uses of Arsenopyrite and Arsenic. Arsenopyrite is the primary ore of arsenic metal. The mineral contains approximately 46% arsenic by weight. Arsenic metal is used to produce a variety of alloys. It was historically used to harden lead in ammunition, but this use was nearly eliminated by the late 1900s. A macroscopic (mixed-flow reactor) and microscopic (hydrothermal atomic force microscopy, HAFM) approach was used to quantify sphalerite (ZnS) dissolution rates and to investigate the stoichiometry of dissolution and leached layer formation. HAFM observations of reacted (110) surfaces at room temperature revealed surface roughening …Formula: ZnS Hardness: 3.5-4 Description: Sulphide mineral with isometric crystal structure and metallic or resinous lustre. Specimen number: R25496.When it comes to protecting your data, wiping a hard drive clean is one of the most effective ways to ensure your information remains secure. With the increasing number of cyber threats, it’s important to take the necessary steps to protect...They often are strikingly coloured and have a low hardness and a high specific gravity. The composition of the sulfide minerals can be expressed with the general chemical formula A m S n, in which A ... The second distinct structural type is that of sphalerite (ZnS), in which each metal ion is surrounded by six oppositely charged ions arranged ...Sphalerite shows a low Fe con-tent of 1.04 % in average and occasionally chalcopy- rite inclusion/disease also occurred. Ga and Ge con-tents are also high in sphalerite. Co>Ni in pyrite, low ...

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Its hardness is 6–7 on the Mohs scale of mineral hardness, making it one of the harder varieties of this particular mineral group. ... Sphalerite. Sphalerite is a mineral composed of zinc sulfide that is commonly found in hydrothermal veins and sedimentary rocks. It comes in a range of colors, including yellow, brown, black, and red, and has ...18 Mar 2022 ... This, combined with its low hardness (3.5 to 4 on the Mohs scale), makes the mineral difficult to cut and polish. Therefore, it's not ...Sphalerite. Luster: metallic or Adamentine (gem like) Hardness: 3.5-4 Cleavage: dodecahedral Streak: light yellow-brown Smells like sulfur. Pyrite.Chalcopyrite has a hardness of 3.5 to 4 on the Mohs scale, a streak that is greenish-black to black, and a specific gravity ranging from 4.1 to 4.3. Chalcopyrite is used primarily for copper production, as it contains copper as a major component and is processed to extract copper for various industrial applications, including electrical wiring ...Because of its low hardness (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 …

Chalcopyrite ( / ˌkælkəˈpaɪˌraɪt, - koʊ -/ [7] [8] KAL-kə-PY-ryte, -⁠koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS 2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale.2.1. Hardness There are numerous ways of estimating hardness in polished surfaces. The relative hardness of minerals can be estimated by the depth and the width of existing scratches from the grinding and polishing procedure (Figure 3a). With some experience a relative hardness estimate can also be made by carefully observing grain boundaries ofIts hardness rating is 3.5-4 on the Mohs scale, its specific gravity is 3.9-4.1, and its refractive index is 2.37 (when measured using sodium light at 589.3 nanometers). Its …Mohs Hardness: 3.5 to 4 . Sphalerite Crystal Healing Properties. Sphalerite crystals contain numerous healing properties. When used consistently, it has a massive impact on our everyday lives. The crystal knows no bounds providing everything from mental health benefits to physical perks. Sphalerite Crystals and HealthIf you’re a fan of McNess products, you know that their specialty items can be hard to find in regular grocery stores. However, fear not. There are still plenty of options available for you to purchase these beloved products.With a hardness of just 3.5 to 4, sphalerite can be scratched very easily. Common household dust, with a hardness of 7, would scratch sphalerite if you wiped it off with a cloth. Faceters also face additional challenges …Sphalerite; Chemical composition (Zn,Fe)S: Crystal system: Cubic: Habit: Tetrahedral or dodecahedral: Cleavage: Perfect in 6 directions; easily developed: Fracture: Concoidal to …Sphalerite ore, also known as blackjack, ruby blende, and zinc blende is a mineral and ore of zinc with a chemical composition of ((Zn, Fe)S). It was discovered by Ernst Friedrich Glocker in 1847, who named it based on the Greek word “sphaleros” meaning deceiving or treacherous because its lustrous dark crystals can be misguided for other minerals.>Galena ~Chalcopyrite <Sphalerite (Hardness varies with composition) Irregular masses of Anhedral grains interstitial to Fe and Cu-Fe sulphides / Rounded inclusions in Galena and Sphalerite: Forms complete solid solution with Tennantite / Growth zoning especially in more As-rich members: Arsenopyrite Galena Sphalerite Study with Quizlet and memorize flashcards containing terms like pyrite luster, Pyrite Hardness, Pyrite cleavage and more. ... Sphalerite luster. metallic. Sphalerite Hardness. 3.5-4. Sphalerite Cleavage. 6 cleavage planes. Sphalerite color. brown/Grey w/ gold and purple specs. sphalerite streak. white, yellow, brown

With a hardness of just 3.5 to 4, sphalerite can be scratched very easily. Common household dust, with a hardness of 7, would scratch sphalerite if you wiped it off with a cloth. Faceters also face additional challenges cutting this stone. It has six perfect cleavage planes in its isometric crystal structure and it’s brittle.

Start studying Geology Lab - Exam One Rocks and Minerals - Kristina Raley - UArk. Learn vocabulary, terms, and more with flashcards, games, and other study tools.Sphalerite’s 3.5-4 hardness ranking means even household dust (at 7 hardness) can scratch it. Therefore, we recommend sphalerite pendants or brooches …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. ... Hardness: 3.5–4 Amount of …Associated minerals include: smithsonite, sphalerite, cerussite, anglesite, and galena. Diagnostic properties in hand specimens are its crystal habit, hardness, specific gravity, and its effervescence with cold hydrochloric acid.Sphalerite is made up of zinc sulfide, the chief ore of zinc, and is a part of the Sphalerite group. Spend $100 or More & Get 60% off - Use Code BULK60 ... Hardness: 3.5 to 4 Hardness: Numerical Vibration: Number 5, Number 6: Chemical Composition: (ZnFe)S, Zinc Sulfide: COMMON CONDITIONS:Sphalerites have a low hardness (3.5 to 4) and perfect cleavage. These properties also make sphalerites less than ideal as jewelry stones. Nevertheless, sphalerites can show beautiful colors and may appeal to collectors of unusual gems. Consult our sphalerite buying guide for more information. Boron nitride nanomesh. Boron nitride nanomesh is a nanostructured two-dimensional material. It consists of a single BN layer, which forms by self-assembly a highly regular mesh after high-temperature exposure of a clean rhodium [80] or ruthenium [81] surface to borazine under ultra-high vacuum.

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Sphalerite Hardiness (Mohs Hardness) Sphalerite is relatively easy, but it can still last a long time. Sphalerite, a primary ore of zinc, has a hardness of 3.5 to 4 on the Mohs hardness scale. Its low hardness and perfect cleavage make it fragile, making it unsuitable for most jewelry. Despite its softness, sphalerite is valued by collectors ...Schalenblende Meanings, Zodiacs, Planets, Elements, Colors, Chakras, and more. Science & Origin of SchalenblendeSchalenblende is a lead-zinc ore that contains compact layers (once botryoidal) of @Galena@, Wurtzite, @Sphalerite@, @Pyrite@, and @Marcasite@. Identifying the minerals within a piece are very easy, yellow being Wurtzite, brown being …19 Eyl 2023 ... Natural Sphalerite Columnar Crystal Scepter Naturally Formed Rough ... Hardness Tester Meter paragraph. US $22.9. 1,000+ sold 4.9. WEST BIKING ...Hardness: 3.5 to 4: Specific gravity: 4.0: Cleavage: Perfect dodecahedral {110} Fracture: Conchoidal: Luster: Adamantine Resinous: Transparency: Transparent to opaque: Streak: White to brown or yellow: Optical Properties: PPL: Colorless to pale brown ... As sphalerite is isotropic, this video is uneventful. Sphalerite in plane polarized light.Sphalerite gemstone is a zinc sulfide stone that comes in many colors but usually autumn shades of orange, brown, and yellow. Is sphalerite a gemstone? Yes! While more common for non-gemstone uses, gem-quality sphalerite …Mineral Identification Key - Table IB. The Mineral Identification Key. Table IB: Minerals with Metallic or Submetallic Luster & Hardness greater than 2½, but less than 5½: (Will not easily mark paper, but can be scratched with a pocket knife.) [ Previous Table ] [ Next Table ] Hardness. Color.Study with Quizlet and memorize flashcards containing terms like Name the physical property (hardness, color, streak, etc.) described by each of the following statements., What term is used to describe the shape of a mineral that has three directions of cleavage that intersect at 90-degree angles?, Describe the cleavage of the minerals listed below. Include the number of directions and degrees ...Dolomite has a hardness of 3 to 4 on the Mohr scale (comparable to calcite). Dolomite also does not scratch since it is harder than glass (which has a hardness of 5.5). ... Malachite 3.5 – 4 light yellow to brown dark brown, black or yellow Cleavage – 6 dir. 4.0 resinous to sub-metallic adamantine Sphalerite ...If so, this list will help you with identification . Start by inspecting a yellow or yellowish mineral in good light, picking a fresh surface. Decide the mineral's exact color and shade. Make a note of the mineral's luster and, if you can, determine its hardness, too. Finally, try to figure out the geologic setting that the mineral occurs in ...Physical properties Sphalerite possesses perfect dodecahedral cleavage, having six cleavage planes. In pure form, it is a semiconductor, but transitions to a conductor as the iron content increases. It has a hardness of 3.5 to 4 on the Mohs scale of mineral hardness. It can be distinguished from similar minerals by its … See moreGalena (hardness = 2.5) and sphalerite (hardness = 3.5–4) are relatively soft minerals, and would not be expected to survive glacial comminution for great distances. Lastly, the sphalerite grains in till in NW Alberta have dissimilar optical and chemical properties compared to the sphalerite at the Pine Point deposits . ….

Nov 30, 2016 · The lack of hardness in this gemstone means that it can break, crack, or scratch easily. Even as brittle as it is, it can still be found in many shapes, sizes and settings. Because Sphalerite is brittle each gemstone contains imperfections. Sphalerite In Jewelry Sphalerite is rarely found in jewelry due to its lack of hardness. 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.Zinc ; Type. Element (Minerals/Ores of) ; Mineral Classification. Sulfide ; Chemical Formula. (Zn,Fe)S (sphalerite) ; Mohs Hardness. 3.5-4 ...Overall, the main difference between hard and soft evidence is that hard evidence is always preferable to softer alternatives, for the simple fact that even the best soft evidence cannot outweigh hard evidence in any form.Sphalerite in Hand Sample. Three small hand samples Sphalerite on fossiliferous chert. Sphalerite in Thin Section Thin Section GigaPans. Sphalerite in plane polars Sphalerite in crossed polars. Sphalerite, …Wurtzite is a zinc and iron sulfide mineral with the chemical formula (Zn,Fe)S, a less frequently encountered structural polymorph form of sphalerite.The iron content is variable up to eight percent. It is trimorphous with matraite and sphalerite.. It occurs in hydrothermal deposits associated with sphalerite, pyrite, chalcopyrite, barite and marcasite.It also …Sphalerite is also referred to as Blende or Zinc Blende, and is the major ore of zinc. ... The density of sphalerite is 3.9-4.2 g/cm 3 and hardness is 3.5 - 4 – between copper penny and fluorite. Global Distribution. Sphalerite is widely distributed, and good examples can be found in the following locations: England - From Alston Moor, Cumbria;Much smithsonite originates when weathering liberates zinc from a deposit's primary mineral - which is often sphalerite. Zinc ore oxidized in the presence of carbon dioxide can result in the formation of smithsonite. ... With a hardness of 4.5, smithsonite is too soft for most jewelry uses, but the mineral is cut into colorful gems for ...Color: Silvery yellow-brown, silvery red, black with sub metallic to resinous luster. Streak: White --> pale yellow brown. Hardness: H 5-6 (Soft/Hard) Cleavage/Fracture: Good --> excellent cleavage. Special Properties: Smells like rotten eggs when scratched, powdered or in acid test (HCl) Galena (90 degree edges) Luster: Metallic. Sphalerite hardness, The hardness test developed by Friedrich Mohs was the first known test to assess resistance of a material to scratching. It is a very simple but inexact comparative test. Perhaps its simplicity has enabled it to become the most widely used hardness test. Since the Mohs Scale was developed in 1812, many different hardness tests have been invented., Fig. I shows a polished surface of a hand specimen of the material involved in most of the experiments--a highly coherent galena-sphalerite-garnet gneiss ..., Streak brownish yellow to orange-yellow. Brittle. Sphalerite (metallic) Submetallic to resinous luster. Color yellow to yellow-brown to dark brown. Hardness=3.5-4. Perfect vleavage in six directions (dodecahedral). Brown, light yellow, to white streak. Cleavage faces common, twinning common., hardness: 3.4 - 4.0 cleavage: perfect color: brown, black, yellow red, green gray streak: brown to yellow luster: resinous specific gravity: 4.63 - 4.66 other: PYRITE HARDNESS: 6 - 6/1/2 CLEAVAGE: INDISTINCTIVE COLOR: FOOLS GOLD, OPAQUE WITH METALLIC GOLD OR SHINEY GOLD STREAK: GREENISH BLACK, BROWN LUSTER: DULL …, ... Hardness · Chakras · Southwest Gem/ Mineral/ Rock Clubs · Taos Rockers' Gem Safari · Size Chart · About. USD, INR, GBP, CAD, AUD, EUR, JPY. 0 $0.00. USD, INR ..., Hardness Streak Cleavage Gravity Other Properties Chemical Composition Specific Mineral 1 - 5.5 Yellowish- None 3.5 - 4 Massive, coatings, botryoidal crusts, earthy Limonite ... Tetrahedron Sphalerite yellowish- shaped crystals. Yellowish-brown to black color. ZnS brown Resinous luster. 5 - 6 Reddish- None. Uneven fracture. 5 Massive, granular ..., Sphalerite is made up of zinc sulfide, the chief ore of zinc, and is a part of the Sphalerite group. Spend $100 or More & Get 60% off - Use Code BULK60 ... Hardness: 3.5 to 4 Hardness: Numerical Vibration: Number 5, Number 6: Chemical Composition: (ZnFe)S, Zinc Sulfide: COMMON CONDITIONS:, Sphalerite is a common mineral, and occurs in many distinct colors and forms. Iron impurities are often present in this mineral, and for this reason it is not commonly transparent. If Sphalerite contains a large amount of iron impurities, it will have a metallic dark gray or black color, which is typical of most sulfide minerals. Sphalerite is one of the few minerals that can range from gemmy ..., The sphalerite crystallizes in cubic system with perfect cleavage, and simple contact twinning. Sphalerite depicts uneven to conchoidal fracture, adamantine, resinous to greasy luster, and brownish white to pale yellow streak. The specific gravity is between 3.9 and 4.2, and hardness between 3.5 and 4.0., Figure 3.5.5 3.5. 5: Limonite, hydrated oxide of iron. After carbonates, the next most common non-silicate minerals are the oxides, halides, and sulfides. Oxides consist of metal ions covalently bonded with oxygen. The most familiar oxide is rust, which is a combination of iron oxides (Fe 2 O 3) and hydrated oxides., Hardness 3.5-4 Streak White Luster Vitreous, pearly Cleavage Rhombohedral Fracture Subconchoidal Density 2.84 - 2.86 g/cm3 Mineral Habit Blocky, crystalline, massive Crystal System Hexagonal Environment of Formation In sedimentary rock; occasionally in high-temperature metamorphic rocks and low-temperature hydrothermal veins. Economic Importance, Uses of Arsenopyrite and Arsenic. Arsenopyrite is the primary ore of arsenic metal. The mineral contains approximately 46% arsenic by weight. Arsenic metal is used to produce a variety of alloys. It was historically used to harden lead in ammunition, but this use was nearly eliminated by the late 1900s., Red Orange Sphalerite Natural Gem Mined From Spain (Limited Stock). $449.99 ... Hardness: 3.5-4. Origin: Spain. Ships from and sold by. www.etsy.com. Visit. Save ..., Sphalerite (cont) Sphalerite (cont) Chemical compos‐ ition (Zn,fe)s Hornblende Hornblende Form Prismatic, Tabular Colour Black, Dark green Lustre Vitreous Streak Colourless Hardness 5- Cleavage Imperfect Fracture Uneven Sp. Gravity 2-3., Study with Quizlet and memorize flashcards containing terms like Name the physical property (hardness, color, streak, etc.) described by each of the following statements., What term is used to describe the shape of a mineral that has three directions of cleavage that intersect at 90-degree angles?, Describe the cleavage of the minerals listed below. Include the number of directions and degrees ..., The hardness of the element copper is measured at 2 1/2 to 3 mohs. The mohs hardness or mohs scale is used to measure the resistance that a smooth surface has towards scratching or abrasion., Bulk Density (Electron Density)=5.70 gm/cc. note: Specific Gravity of Arsenopyrite =6.19 gm/cc. Fermion Index: Fermion Index = 0.0087478423. Boson Index = 0.9912521577. Photoelectric: PEArsenopyrite = 44.13 barns/electron. U=PEArsenopyrite x r Electron Density= 251.61 barns/cc. Radioactivity:, They often are strikingly coloured and have a low hardness and a high specific gravity. The composition of the sulfide minerals can be expressed with the general chemical formula A m S n, in which A ... The second distinct structural type is that of sphalerite (ZnS), in which each metal ion is surrounded by six oppositely charged ions arranged ..., you determine the hardness of a mineral not listed on the Mohs scale, such as sphalerite? You could try to scratch sphalerite with talc, gypsum, or calcite. But ..., Dec 9, 2008 · Sphalerite is a relatively soft gem, with a hardness of only 3.5 to 4 on the Mohs scale, about the same as fluorite. So despite its amazing fire, it is not suitable for everyday-wear rings. It has a density or specific gravity of 3.90 to 4.10, making it one of the denser gems, similar to sapphire and ruby, but not quite as dense as zircon. , Rough Jewelry Table of Contents General Information Sphalerite Colors Alternate Names Countries of Origin Care Related Videos Sphalerite makes an excellent collector's stone, but it is too soft for jewelry. It is difficult to cut and polish due to perfect cleavage in six directions., Chalcopyrite ( / ˌkælkəˈpaɪˌraɪt, - koʊ -/ [7] [8] KAL-kə-PY-ryte, -⁠koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS 2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. , APPROX. WEIGHT 1.60 cts. SHAPE Round cut. SIZE 6,44 x 4,76 mm. COLOR Orange CLARITY IF LUSTER Excellent ORIGIN Santander, Spain HARDNESS 3.5-4, Description: Sphalerite is the most common and important zinc mineral. Sphalerite has a beautiful shine, but is very soft, and it’s color varies. Sphalerite is non-metallic. Uses: Galvanized iron, batteries, brass. Used in mildew resistant element in some paint. Sphalerite is used in dyes, medicine, and more., brown streak; hardness of 1-3. Deep blue; crusts, small crystals, or massive ... Sphalerite. Fluorite. Biotite. Mica. Chlorite. Limonite. Bauxite. Azurite., Hardness: 2 Cleavage: Good in 1 poor in 2 Luster: Vitreous, pearly or silky Tenacity: Flexible Diaphaneity: Transparent to opaque ... Sphalerite. Hardness: 3.5 - 4 Cleavage: 6 directions Luster: resinous (root beer) Streak: light …, [1] The name sphalerite is from the Greek word "sphaleros" which means deceiving or treacherous. This name is in response to the many different appearances of sphalerite and because it can be challenging to identify in hand specimens. , Study with Quizlet and memorize flashcards containing terms like streak, hardness, clevage and more., The hardness of the element copper is measured at 2 1/2 to 3 mohs. The mohs hardness or mohs scale is used to measure the resistance that a smooth surface has towards scratching or abrasion., 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., As noted above, sphalerite can be found in various colors, particularly yellow, brown, and gray to gray-black. It has a yellow or light brown streak. Its hardness rating is 3.5-4 on the Mohs scale, its specific gravity is 3.9-4.1, and its refractive index is 2.37 (when measured using , Two minerals of note have differences in hardness depending on direction: Kyanite has a hardness of 5 parallel to the length of the crystal, and a hardness of 7 when scratched along a direction perpendicular to the length. Calcite has a hardness of 3 for all surfaces except the {0001} plane. On {0001} it has a hardness of 2., Sphalerite is a mineral that consists largely of zinc sulfide in crystalline form, but it almost always contains variable amounts of iron. Its chemical formula may therefore be written as (Zn,Fe)S. ... Its hardness rating is 3.5-4 on the Mohs scale, its specific gravity is 3.9-4.1, and its refractive index is 2.37 ...