Streak. Diamond is the hardest mineral; no other mineral can scratch a diamond. The Moh’s Scale of Hardness ranks minerals, materials, metals and Gemstones on a scale of 1-10. Rocks are made up of one or more minerals. Forms X-shaped crystals. [7], The Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly. Topaz. It is also ductile, meaning it can be drawn into wire. Diagnostic Properties Hardness: 2.5-3 - Finger Nail-Calcite : Luminescence: Non-fluorescent. 2.5-3 Rocks are made up of one or more minerals. Hardness is 2.5-3. Veins and other ore deposits. Home Mining & Minerals Information Minerals Database. Polyhalite Polyhalite is an evaporite mineral that is a hydrated sulfate of potassium, calcium and magnesium with a relative hardness of 4. Fluorite is one. Ag. The tarnish is commonly either the oxide or the sulfide of silver. GeoMan's Mineral Identification LUSTER: Non-metallic Streak Colorless or Light Colored Hardness: 2.5 to 3.5 (cannot be scratched with thumbnail; will not scratch penny) Common 12- or 24-sided crystals. Cubic cleavage. It can be scratched by topaz, corundum, and diamond. Sterling Silver is harder and more durable than pure Silver. In Move Mining Next Gen, students from grades K-12 create and submit short, 3-minute videos to answer the question, “Why is mining important in our lives?”  There are prizes for a grades K-5 category ($250), a grades 6-8 category ($250) and a grades 9-12 category ($250), as well as an overall winner ($1,000). Minerals are chemically pure solids found in nature. 8. As a result, it was used in ancient times to make mirrors. Mohs Hardness. It is primarily found as a constituent of hydrothermal veins. "Size reduction, comminution - grinding and milling",, "Mohs Hardness Scale: Testing the Resistance to Being Scratched", "Material Hardness Tables, Ted Pella, Inc", "Advancements in the Search for Superhard Ultra-Incompressible Metal Borides",, Creative Commons Attribution-ShareAlike License, This page was last edited on 9 December 2020, at 05:57. There is an additional prize ($500) for the video that receives the most votes online—the People’s Choice winner. Suppose you had a piece of pure gold. Prismatic and X or cross shaped crystals. The design and re-launch of the new MEC website is madepossible by a generous contribution from Newmont Mining, The SciFest All Access virtual science festival will offer engaging STEM activities and performances, The design and re-launch of the new MEC website is made. The Comstock lode district was perhaps the largest single silver ore find ever made in the USA. Link to Location Data. It is located in Group 11 of the periodic table. For example, if some material is scratched by apatite but not by fluorite, its hardness on the Mohs scale would fall between 4 and 5. Red-brown to brownish-black. As the hardest known naturally occurring substance when the scale was designed, diamonds are at the top of the scale. Chemical Formula. Spinel. [6] The scale is used at electronic manufacturers for testing the resilience of flat panel display components (such as cover glass for LCDs or encapsulation for OLEDs). 2) … High specific gravity. Specific Gravity is variable according to purity 10-12 (well above average even for metallic minerals) Associated Minerals are silver minerals such as acanthite and prousite , cobaltite , copper , zeolites and quartz . 9. Fresnillo, Zacatecas, and Guanajuato, Mexico and other silver districts in the world. Name Pronunciation: Pyrargyrite + Pronunciation : Synonym: Dark Red Silver Ore : ICSD 38389 : PDF 21-1173 : Ruby Silver Ore The table below shows the comparison with the absolute hardness measured by a sclerometer, with pictorial examples. The MEC Virtual Booth has the new MEC Careers in Mining video and more! silver: 2.5: 250: 245–250: 206 48: Cd: cadmium: 2.0: 203–220: 196 49: In: indium: 1.2: 8.83-10: 9.8 50: Sn: tin: 1.5: 51–75: 292–441 (cast) 51: Sb: antimony: 3.0: 294–384: 52: Te: tellurium: 2.25: 180–270: 55: Cs: caesium: 0.2: 0.147: 56: Ba: barium: 1.25: 57: La: lanthanum: 2.5: 360–1750: 350–400: 58: Ce: cerium: 2.5: 210–470: 186–412: 59: Pr: praseodymium: 250–746: 250–638: 60: Nd: neodymium: … Likewise, it has been used for silverware. The samples of matter used by Mohs are all different minerals. Silver is commonly extracted from ore by smelting or chemical leaching. Mohs hardness is useful in milling. Most widespread minerals containing Silver; This list of minerals containing Silver is built from the locality database. Silver Mineral Facts: Chemical Formula: Ag - Silver . Go to to learn how to make and submit your video! Gold and Silver on the other hand are only a 2.5 – 3 on the Moh’s Scale. Gold-Silver Series and Palladium-Silver Series. Whitens when naturally alloyed with silver. It allows assessment of which kind of mill will best reduce a given product whose hardness is known. A natural alloy of gold and silver is known as Electrum, and is usually classified as a variety of Gold. 10 being the best and the most durable… Diamond is a 10. It is an ore of silver and resembles hematite but is much softer. It has been used by dentists in amalgam fillings. Diaphaneity: Opaque: Cleavage: None: Mohs Hardness: 2.5 to 3: Specific Gravity: 19.3 when pure. Hardness: Color: Streak: Cleavage: Name: System: Habit: SG: Notes: 3: Grey-black: Black: One perfect (prismatic), two distinct, and one indistinct direction: ENARGITE Cu 3 AsS 4: Orthorhombic: Usually in bladed masses: 4.4: Crystals vertically striated Historically, to increase hardness, copper was added to silver and the way in which this affects the annealed hardness of the resulting silver-copper alloys is shown in the Hardness Increase with Copper Content graph. Diamond. ADamas: six varieties of it. If your mineral does NOT scrape the penny, record the hardness as 2.5