Classifying minerals can range from simple to very difficult. A mineral can be identified by several physical properties, some of them being sufficient for full identification without equivocation. In other cases, minerals can only be classified by more complex chemical or X-ray diffraction analysis; these methods, however, can be costly and time-consuming. Physical properties commonly used are: * Crystal structure and habit: See the above discussion of crystal structure. A mineral may show good crystal habit or form, or it may be massive, granular or compact with only microscopically visible crystals.
* Hardness: the physical hardness of a mineral is usually measured according to the Mohs scale. This scale is relative and goes from 1 to 10. Minerals with a given Mohs hardness can scratch the surface of any mineral that has a lower hardness than itself. * ** Mohs hardness scale: # Talc Mg3Si4O10(OH)2 # Gypsum CaSO4·2H2O # Calcite CaCO3 # Fluorite CaF2 # Apatite Ca5(PO4)3(OH,Cl,F) # Orthoclase KAlSi3O8 # Quartz SiO2 # Topaz Al2SiO4(OH,F)2 # Corundum Al2O3 # Diamond C (pure carbon) * Luster indicates the way a mineral's surface interacts with light and can range from dull to glassy (vitreous). ** Metallic -high reflectivity like metal: galena and pyrite ** Sub-metallic -slightly less than metallic reflectivity: magnetite ** Non-metallic lusters: *** Adamantine - brilliant, the luster of diamond also cerussite and anglesite *** Vitreous -the luster of a broken glass: quartz *** Pearly - iridescent and pearl-like: talc and apophyllite *** Resinous - the luster of resin: sphalerite and sulfur *** Silky - a soft light shown by fibrous materials: gypsum and chrysotile *** Dull/earthy -shown by finely crystallized minerals: the kidney ore variety of hematite * Color indicates the appearance of the mineral in reflected light or transmitted light for translucent minerals (i.e. what it looks like to the naked eye). ** Iridescence - the play of colors due to surface or internal interference. Labradorite exhibits internal iridescence whereas hematite and sphalerite often show the surface effect. * Streak refers to the color of the powder a mineral leaves after rubbing it on an unglazed porcelain streak plate. Note that this is not always the same color as the original mineral. * Cleavage describes the way a mineral may split apart along various planes. In thin sections, cleavage is visible as thin parallel lines across a mineral. * Fracturedescribes how a mineral breaks when broken contrary to its natural cleavage planes. ** Chonchoidal fracture is a smooth curved fracture with concentric ridges of the type shown by glass. ** Hackley is jagged fracture with sharp edges. ** Fibrous ** Irregular * Specific gravityrelates the mineral mass to the mass of an equal volume of water, namely the density of the material. While most minerals, including all the common rock-forming minerals, have a specific gravity of 2.5 - 3.5, a few are noticeably more or less dense, e.g. several sulfide minerals have high specific gravity compared to the common rock-forming minerals. * Other properties: fluorescence (response to ultraviolet light), magnetism, radioactivity, tenacity (response to mechanical induced changes of shape or form), piezoelectricity and reactivity to dilute acids.
To determine the density of a mineral, you need to know its mass and volume. The mass of the mineral can be measured using a balance, while the volume can be determined using displacement method or by measuring its dimensions and calculating the volume. Density is calculated by dividing the mass of the mineral by its volume.
Yes, it is possible to quickly determine the hardness of one mineral relative to that of another mineral using the Mohs scale of mineral hardness. This scale ranks minerals based on their ability to scratch one another, allowing for a straightforward comparison. By performing scratch tests, you can ascertain which mineral is harder or softer relative to the other.
You can determine the streak of a mineral whose Mohs scale is higher than the streak plate by either filing or crushing with a hammer before rubbing the sample on a streak plate.
Concentration factor in mineral exploitation refers to the ratio of the concentration of a valuable mineral in the ore to the concentration of the same mineral in the Earth's crust. It is used to determine the economic viability of mining a particular mineral deposit. A higher concentration factor indicates that the mineral is more concentrated in the ore and thus easier and more cost-effective to extract.
No, the ratio of silicon to oxygen can vary among different silicate minerals. The overall structure and composition of the mineral will determine the specific ratio of silicon to oxygen present in that mineral.
If you are starting with a mineral, there is no need to determine if it is a mineral. Minerals are naturally occurring inorganic solids, with a specific chemical formula and a crystalline structure. If the material in question does not meet this definition, it probably isn't a mineral.
by rubbing the mineral on a rough hard surface
by rubbing the mineral on a rough hard surface
Color: Observe the color of the mineral. Hardness: Use the Mohs scale to determine the mineral's hardness. Cleavage and fracture: Check how the mineral breaks. Luster: Determine if the mineral is metallic or non-metallic. Streak: Identify the color of the mineral's powdered form. Specific gravity: Measure the density of the mineral. Acid reaction: Test if the mineral reacts with acid.
The density of the mineral compared to the density of water will determine if it floats or sinks. If the mineral has a lower density than water, it will float; if it has a higher density, it will sink.
The Mohs mineral hardness scale.
The color of a mineral in powdered form is called the mineral's Streak
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An index mineral is used in geology to determine the degree of metamorphism a rock has experienced.
An index mineral is used in geology to determine the degree of metamorphism a rock has experienced.
The color of a mineral in powdered form is called the mineral's Streak
it determines the hardness of a mineral.