The hardness of sphalerite is relatively low, 3.5-4 in the Mohs scale, which is the reason to use these gems mainly for collections. Moreover, sphalerite presents a perfect cleavage in 6 different directions, corresponding to faces of a rhombic dodecahedron, which means additional faceting difficulties.Sphalerite (Zn,Fe)S c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Cubic. Point Group: 43m. Crystals tetrahedral, dodecahedral, typically complex and distorted, curved and conical faces common, to 30 cm. Also fibrous, botryoidal, stalactitic, cleavable, coarse to fine granular, massive. Twinning: Twin axis [111], twin planeStep 5/5. Final answer. Transcribed image text: The hardness of these mineral specimens is a direct consequence of the strength of the molecular bonds that bind them together. Conversely, this can be related to the energy required, during mineral processing, to break these bonds and liberate the metal of economic interest.Ash has a hardness rating of 1200 (most scales generally agree, but sometimes they may be slightly different in number). For comparison, one of the strongest and hardest wood available is hickory with a hardness rating of 1820 while the strong oak has a rating of 1290. This puts ash right at the top with some of the hardest wood options …Sphalerite. While most fluorescent specimens of the mineral exhibit an orange fluorescence, sphalerite can fluoresce in a rainbow of colors. A zinc sulfide, sphalerite is the most common and most important zinc ore in world. Sphalerite typically occurs as well-formed crystals in a variety of sizes. Interestingly, micro-crystals of sphalerite …Galena’s hardness is similar to that of a fingernail, so it is easily scratched by a nail or metal implement. In Our Earth: The Geologic Importance of Galena The most common and widespread lead mineral, galena occurs in low-temperature to medium-temperature hydrothermal veins in igneous rocks, pegmatites, and contact-metamorphosed sedimentary rock.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.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.Mohs hardness kit, containing one specimen of each mineral on the ten-point hardness scale. The Mohs scale of mineral hardness (/ m oʊ z /) is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of minerals through the ability of harder material to scratch softer material.. The scale was introduced in 1812 by the German geologist and …Although sphalerite (SFAL-er-ite) has a hardness of only 3 1/2 to 4 and possesses six directions of perfect dodecahedral cleavage, transparent stones are highly prized by collectors because of the mineral's tremendous dispersion (0.156) and R.I. (about 2.37). The resultant brilliancy and fire displayed by green, greenish-brown, yellow-brown or reddish …Yellow sphalerite is a very brittle stone with a hardness of 3-3.5. Yellow sphalerite from Mexico can be very large and most often occurs in yellowish-orange tones. It also 3x more dispersion than a yellow diamond! Fine colored gems that are red and vivid orange stones above 3 carats.Chalcopyrite is a striking, bright yellow, metallic mineral that occurs in nearly all sulfide deposits. Initially, it may be easy to confuse chalcopyrite, or copper pyrite (CuFeS2), with pyrite (FeS2), but the two can be distinguished by their relative hardness and chalcopyrite’s iridescent tarnish. 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.Geologists use the Mohs Hardness scale and the items on the scale to determine the hardness of a mineral sample. Learn how to use the scale when identifying ...Sphalerite is a zinc ore containing iron. When its iron is high, its color becomes matte black. Materials that have the quality of jewels have less iron content and as a result their …Step 5/5. Final answer. Transcribed image text: The hardness of these mineral specimens is a direct consequence of the strength of the molecular bonds that bind them together. Conversely, this can be related to the energy required, during mineral processing, to break these bonds and liberate the metal of economic interest.Aug 11, 2018 · The sphalerite chemical formula is ZnS (zinc sulfide.) This chemical formula represents sphalerite in its pure form, but it is much more commonly found with significant amount of other elements substituting zinc. Up to 26 % Fe, 17 % Cd, 15 % Hg, 21 % Mn and small amounts of Cu, In, Ga, Ge and As may replace the zinc. Cooking hard boiled eggs can be a tricky task. If you don’t get the timing just right, you can end up with an egg that is either undercooked or overcooked. But even if you do get the cooking time perfect, peeling the egg can be a challenge....Although sphalerite (SFAL-er-ite) has a hardness of only 3 1/2 to 4 and possesses six directions of perfect dodecahedral cleavage, transparent stones are highly prized by collectors because of the mineral's tremendous dispersion (0.156) and R.I. (about 2.37).... Hardness: 3.5-4. Data courtesy of Webmineral. Collection: Arnold G Hampson Collection. Mineralpedia: View Sphalerite; On Dakota Matrix: Previously Sold ...Although sphalerite (SFAL-er-ite) has a hardness of only 3 1/2 to 4 and possesses six directions of perfect dodecahedral cleavage, transparent stones are highly prized by collectors because of the mineral's tremendous dispersion (0.156) and R.I. (about 2.37). The resultant brilliancy and fire displayed by green, greenish-brown, yellow-brown or reddish …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. 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.Sphalerite occurs in a wide range of colors, including bluish-green, brown, colorless, green, orange, red, yellow, and yellowish-green. However, most gem- ...6 ago 2020 ... For example for hematite and sphalerite, which have very similar photo image, are in different Mohs hardness range. Hematite is in the range of ...what is the hardness of salt crystal, Feldspar crystal, Quartz crystal, Calcite crystal, and Sphalerite crystal. This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts.Comments: Polished section (PPL) showing crystalline aggregate of arsenopyrite (asp) in massive sphalerite (sp), typical of the main sphalerite lens. Location: Giant Kidd Creek Volcanogenic Massive Sulfide deposit, Western Abitibi Subprovince, Timmins, Ontario, Canada. ... Hardness: 5 - Apatite : Luminescence: Non-fluorescent. Luster: Metallic : …White or colorless (about the same hardness as the streak plate). Silver: Silvery white. Sodalite: White or light blue. Sphalerite: White to yellowish brown, often with an odor of sulfur. Spinel: Colorless (harder than the streak plate). Spodumene: White or colorless (about the same hardness as the streak plate). Staurolite: Colorless (harder ... 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 SciencesThe 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.After having a computer for a few years, your hard drive can become just as personal as a diary. Over time, you collect countless files, from pictures to documents to passwords and other personal information, that is essentially irreplaceab...The hardness is 5 and the calculated specific gravity is 4.5. Chemistry and ... sphalerite, tetrahedrite, lollingite, arsenopyrite and bismuth. It is found ...13 jul 2023 ... Polishing hardness between that of sphalerite and chalcopyrite (PolHalb < sp; PolHalb > ccp). Vickers Microhardness, VHN, increases with Fe ...Mar 31, 2014 · Sphalerite is a zinc ore mineral that typically contains iron. When it has a high iron content, sphalerite is an opaque black. Gem-quality material has a low iron content, resulting in transparent crystals. Due to its lack of hardness, it is mainly a collector's gemstone. One of the most notable characteristics of sphalerite is its high ... Diamond has a hardness of 10 (hardest) on this scale ,it is the hardest natural material known. The gemstone hardness in this chart would help reduce damages while mounting a gemstone in jewellery, and endure the occasional hard knock or abrasion. Note: A fingernail has a hardness of 2; a copper penny, about 3; a knife blade, 5; window glass, 5 ...Galena’s hardness is similar to that of a fingernail, so it is easily scratched by a nail or metal implement. In Our Earth: The Geologic Importance of Galena The most common and widespread lead mineral, galena occurs in low-temperature to medium-temperature hydrothermal veins in igneous rocks, pegmatites, and contact-metamorphosed sedimentary rock.It has a hardness of 3.5 to 4 on the Mohs scale of mineral hardness. [20] It can be distinguished from similar minerals by its perfect cleavage, its distinctive resinous luster, and the reddish-brown streak of the darker varieties. [21] Optical propertiesGalena’s hardness is similar to that of a fingernail, so it is easily scratched by a nail or metal implement. In Our Earth: The Geologic Importance of Galena The most common and widespread lead mineral, galena occurs in low-temperature to medium-temperature hydrothermal veins in igneous rocks, pegmatites, and contact-metamorphosed sedimentary rock.Maghemite (γ-Fe2O3) is a mineral formed from magnetite oxidation at low temperatures, an intermediate metastable term of the magnetite to hematite oxidation and could be mixed with both.It has a hardness of 3.5 to 4 on the Mohs scale of mineral hardness. [20] It can be distinguished from similar minerals by its perfect cleavage, its distinctive resinous luster, and the reddish-brown streak of the darker varieties. [21] Optical propertiesStreak 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.Wurtzite. Brownish black, Orange brown, Reddish brown, Black. Radial clusters and colloform crusts and masses. Also as tabular crystals. 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. [5]Here are five things to know about this unique gemstone. 1. It has another name. Sphene comes from the Greek word “sphenos,” meaning wedge, a reference to the mineral’s characteristic wedge-shaped crystals. But it also goes by the name titanite, referencing its place in the mineral group.Indium was discovered in 1863 by Ferdinand Reich at the Freiberg School of Mines in Germany. Reich was investigating a sample of the mineral zinc blende (now known as sphalerite, ZnS) which he believed might contain the recently discovered element thallium.White or colorless (about the same hardness as the streak plate). Silver: Silvery white. Sodalite: White or light blue. Sphalerite: White to yellowish brown, often with an odor of sulfur. Spinel: Colorless (harder than the streak plate). Spodumene: White or colorless (about the same hardness as the streak plate). Staurolite: Colorless (harder ... Chalcopyrite is a striking, bright yellow, metallic mineral that occurs in nearly all sulfide deposits. Initially, it may be easy to confuse chalcopyrite, or copper pyrite (CuFeS2), with pyrite (FeS2), but the two can be distinguished by their relative hardness and chalcopyrite’s iridescent tarnish.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 usingSphalerite 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, sphalerite will break ... 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, marmatite and pyrite ... Sphalerite has been previously called blende or later zinc blende. Its name is from the Greek word ... This mineral is not very hard, registering at 3.9 to 4.1 on the Mohs scale of hardness, and it is brittle. It features a metallic or sub-metallic luster, and may also be resinous or adamantine. It can be black, gray, brown ...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. what is the hardness of salt crystal, Feldspar crystal, Quartz crystal, Calcite crystal, and Sphalerite crystal. This problem has been solved! You'll get a detailed solution from a subject matter expert that helps you learn core concepts.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 SciencesPyrite is harder than sphalerite, with a Mohs hardness of 6 to 6.5 compared to sphalerite’s Mohs hardness of 3.5 to 4. Pyrite also has a higher specific gravity than sphalerite, meaning it is denser and heavier. Using pyrite and sphalerite interchangeably can lead to serious consequences in certain applications. All you need to know about sphalerite - Wiki about minerals. Le Comptoir Géologique Minerals, Fossils, Tumbled Stones, Gemstones and Jewelry - Collection - Lithotherapy - Reiki; ... ore of these rare metals. The clear and transparent varieties are sometimes cut and used as gemstones, but their low hardness confines them rather to stones for collection. …D)zincite, sphalerite, and smithsonite, but not willemite 46.A mineral with a hardness of 5 would scratch Base your answers to questions 47 and 48 on the diagram below, which shows the results of threewhich has a hardness of about 2.5, a copper penny (3.5), and a piece of glass (5.5). The mineral gypsum, which has ahardness of 2, can be easily scratched with a fingernail. On the other hand, the mineral calcite, which has a hardness of 3, will scratch a fingernail but will not scratch glass. Quartz, one of the hardest commonHardness greater than 5.5. Mineral Specimen C. Biotite A cleavage in one plane. Mineral Specimen D. Calcite cleavage in three planes not at 90º angles effervesces. Mineral Specimen E. Gypsum Hardness is under 2.5. Mineral Specimen F. Fluorite 4 Planes of cleavage. Mineral Specimen G. Magnetite Attracts magnet. Mineral Specimen H.21. Sphalerite - ZnS - Usually no problems. Pale yellow streak distinctive. Streak has “rotten egg” odor. 22. Apatite - Calcium phosphate - variable color, hardness of 5, prismatic habit (6 sided), poor cleavage parallel to base, streak always white. This is what your bones and teeth are made of. 23. Corundum - Al 2 O 3 Research highlights Sphalerite dissolution was studied by mixed-flow reactor and HAFM experiments. At 125 °C, {110} surfaces likely transformed into {111} facets with visible step retreat. The morphological transition correlated with an initial dissolution rate maximum. Zn/S release rate ratios did not support extensive leached layer formation. A high apparent activation energy pointed to ...Physical properties The hardness of sphalerite is relatively low, 3.5-4 in the Mohs scale, which is the reason to use these gems mainly for collections.Moreover, sphalerite presents a perfect cleavage in 6 …Apr 23, 2023 · Composition The chemical formula (Zn, Fe) of sphalerite is S. It is a zinc sulphide containing a variable amount of iron instead of zinc in the mineral lattice. configuration is known as cubic sphalerite or zinc blende. Figure 3-1 shows a unit cube for GaAs and Table 3-1 provides a listing of some of the general material characteristics and properties. A [100] [001] [010] Figure 3-1. Unit cube of …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.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 Sphalerite, silver being Galena, and grey and gold ...Sphalerite, zinc sulfide, zinc blende, blende, mock ore, mock lead, black jack, zinc iron sulfide (Zn, Fe)S, has black colour, but other colours also occur, Mohs scale of hardness 3.5-4, yellow to brown streak, diamond-like to submetallic lustre, good cleavage in 6 directions, specific gravity 3.9-4.1.8 may 2013 ... Sphalerite can be identified in the field by its brown, yellow, red, green and black color variations. The appearance of this mineral is ...Hemimorphite most frequently occurs as the product of the oxidation of the upper parts of sphalerite bearing ore bodies, accompanied by other secondary minerals which form the so-called iron cap or gossan. Hemimorphite is an important ore of zinc and contains up to 54.2% of the metal, together with silicon, oxygen and hydrogen. The crystals are ...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. Mustafa 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 ...White or colorless (about the same hardness as the streak plate). Silver: Silvery white. Sodalite: White or light blue. Sphalerite: White to yellowish brown, often with an odor of sulfur. Spinel: Colorless (harder than the streak plate). Spodumene: White or colorless (about the same hardness as the streak plate). Staurolite: Colorless (harder ... The hardness of sphalerite is relatively low, 3.5-4 in the Mohs scale, which is the reason to use these gems mainly for collections. Moreover, sphalerite presents a perfect cleavage in 6 different directions, corresponding to faces of a rhombic dodecahedron, which means additional faceting difficulties.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 is a soft stone. With a hardness of only 3.5-4 on the Moh’s scale, it’s normally too soft to be used in jewelry. Moreover, sphalerite’s perfect cleavage in 6 directions means additional care and attention are required for every step of the fashioning process. The specific gravity of 3.9-4.2 puts this mineral in the same range ...Sphalerite (ZnS) is the primary zinc ore in Missouri. Sphalerite currently is produced from multiple mines in the southeastern part of the state, where it is associated with lead, copper and silver. ...Chalcopyrite is a striking, bright yellow, metallic mineral that occurs in nearly all sulfide deposits. Initially, it may be easy to confuse chalcopyrite, or copper pyrite (CuFeS2), with pyrite (FeS2), but the two can be distinguished by their relative hardness and chalcopyrite’s iridescent tarnish.Mustafa 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 ...Zinc Sulphide FLIR (ZnS) SDS. Zinc Sulphide FLIR (ZnS) Data Sheet. ZnS FLIR is used for IR windows and lenses in the thermal band (8 to 14 μm) as a tough front optic in thermal imaging systems, particularly those subjected to harsh environments. ZnS FLIR grade is harder than ZnS multispectral grade. References & Notes.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 (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 …The color ranges from yellow, golden yeelow, orangy yellow, reddish orange, light to dark brown, black, and some rare colourless and light blue. The light ...sphalerite (ZnS) and pyrite (FeS2) to be exploited in flotation and/or magnetic separation by using microwave energy because these minerals are the main constituents of the complex ore deposits all over the world. Material and experimental study Sphalerite, galena and pyrite samples used in the experimentsStreak 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.Sphalerite and galena also occur as interstitial grains in massive sulfide and adjacent to silicate inclusions. The arsenides, niccolite and maucherite, and sulfarsenides, gersdorffite and cobaltite, commonly occur together, but are largely restricted to the South Range mineral systems that have undergone some degree of structural modification ( Fig. 4.2 …Mar 12, 2022 · Sphalerite’s 3.5-4 hardness ranking means even household dust (at 7 hardness) can scratch it. Therefore, we recommend sphalerite pendants or brooches over a sphalerite ring. To clean sphalerite safely, use a soft toothbrush, mild soap, and lukewarm water. D)zincite, sphalerite, and smithsonite, but not willemite 46.A mineral with a hardness of 5 would scratch Base your answers to questions 47 and 48 on the diagram below, which shows the results of threeSpecimen is about 4.3 x 3.2 x 1.8 centimeters in size. Specimen and photo by Arkenstone / www.iRocks.com. What is Sphalerite? Sphalerite is a zinc sulfide mineral with a chemical composition of (Zn,Fe)S. It is found in metamorphic, igneous, and sedimentary rocks in many parts of the world. It has a yellow or light brown streak, a hardness of 3.5 - 4, and a specific gravity of 3.9-4.1. Some specimens have a red iridescence within the gray-black crystals; these are called "ruby sphalerite." The pale yellow and red varieties have very little iron and are translucent. The darker more opaque varieties contain more iron.Sphalerite : Relative density: 7.14 g/cm 3: Hardness: 2.5 on Mohs scale : Malleability: Brittle, but high when heated : Ductility: Low ductility, but high when heated : Melting point: 420°C : Boiling point: 907°C: Uses. The construction, transport and appliance manufacturing industries use large amounts of zinc, mainly as anti-corrosion coatings …Mohs hardness, specific gravity, habit or form, fracture or cleavage, refractive ... sphalerite, brown, black, yellow; also variable, resinous to adamantine, 3 1/ ...The luster, hardness, and color of orthoclase may be similar to, Sphalerite is a zinc ore containing iron. When its iron is high, its color becomes matte, Hardness Streak Cleavage Gravity Other Properties Chemical Composition Specific Mineral 1 - 5.5 Yellowish- None 3.5 - , Sphalerite is a zinc ore mineral that typically contains iron. When it has a high iron content, sphalerite is a, Hardness Streak Color Cleavage and Fracture Mineral Color, Specific Gravity, etc. Luster Min, Nov 25, 2022 · Sphalerite is an ore mineral consisting of z, Pure Sphalerite has a white streak. However, impurities ar, Two minerals of note have differences in hardness dependi, One of the most striking examples of this is kyanite, which, Formula: Cu Luster: M Hardness: 2.0-3.0 Streak: Copper Sp, Specimen is about 4.3 x 3.2 x 1.8 centimeters in size. , Mar 12, 2022 · Sphalerite’s 3.5-4 hardness ranking mea, Its Mohs hardness is 3.5 to 4. It commonly occurs as tetrah, Fracture. The fracture surfaces of the three steels after tensile , Mohs Hardness: 3.5 to 4: Specific Gravity: 4.1 to 4.3: D, Two minerals of note have differences in hardness depending on , Sphalerite is an ore—a mineral of economic value—that was once, Specimen is about 4.3 x 3.2 x 1.8 centimeters in size. Specimen and.