streak test
Colors are not a reliable method for identifying a mineral because different minerals can have the same color. Take Calcite, Halite and Gypsum for example. At first glance, all three of them appear to be the same mineral. All three of them even have the same streak and luster. However, they all have a different hardness. Calcite has a hardness of three, Halite has 2.5 and Gypsum has 2. Halite is made out of Sodium Chloride, but I wouldn't recommend tasting your mineral samples.
Solid Minerals such as Gold and Copper are mostly mined using the Open Cast Method.
One of the main methods of identifying rocks is by their method of formation. Igneous rock from melt; metamorphic rock from heat/pressure;sedimentary rock from lithification of sediment or precipitation. Then add in the myriad of possible combinations and percentages of minerals that may comprise the rock, and sometimes the identification of a rock can be a daunting task. Minerals are identified by their chemical composition, their crystalline structure, their specific gravity, hardness, streak, and other physical properties.
One of the main methods of identifying rocks is by their method of formation. Igneous rock from melt; metamorphic rock from heat/pressure;sedimentary rock from lithification of sediment or precipitation. Then add in the myriad of possible combinations and percentages of minerals that may comprise the rock, and sometimes the identification of a rock can be a daunting task. Minerals are identified by their chemical composition, their crystalline structure, their specific gravity, hardness, streak, and other physical properties.
A rock's color may be an indication of its mineral content. Some generalizations--A red coloration usually indicates the prescence of iron, small grayish crystals are usually quartz, greenish or bluish colorations indicate a copper content, while white may indicate a feldspar mineral or quartz.
It can be helpful because when you try to find Hemiatite it has various colors. But when you do a streak test the color always turns out red. So it depends on the kind of rock in the groups.
Color-- this varies depending on the chemicals present and is the least informative in identifying a mineral varietyLuster-- what the surface looks like in the lightSpecific Gravity-- how heavy it feels, heftCrystal Form-- shape of crystal, shape the mineral would take if it had room to grow in a cavity, not massive -- some minerals have a number of different crystal shapesCleavage-- pattern when mineral is broken -- in planes or conchoidalFractureTenacity - toughness, how cohesive the mineral is, if it falls apartHardness-- what it can scratch & what scratches itTransparency- The ability to transmit light. Depending on a number of things, rocks & minerals can also transmit light. Many rocks that are opaque when in a chunk, are translucent when cut into very thin slices. Gems stones are often valued on how clear, or transparent they are.
Hardness in a mineral generally refers to its position on the Mohs scale of mineral hardness, which is a scale of ten index minerals rated from softest (#1) to hardest (#10). Hardness on the Mohs scale is the ability of a given mineral to scratch any mineral below it on the scale, and conversely, the inability of a given mineral to scratch any mineral above it on the scale. Rock hardness is measured differently because a rock is usually composed of two or more minerals, giving it a variable Mohs hardness. Hardness of a rock is most often defined as the ability to resist fracture, and by this standard, it is often the method of the rock's formation and mineral content which determines its hardness. For instance, an igneous rock like granite which cooled from magma has an interlocking crystalline structure of quartz and feldspar minerals is extremely resistant to fracture compared to a sedimentary rock like shale, which is formed from loosely cemented particles of clay minerals.
there are many tests but flame test, colour and spectroscopy..are the prilimnary tests for identifying metals.
Streak is a method used to help identify minerals. A mineral can have very similar characteristics such as luster, colour, hardness, specific gravity ect, but even minerals with very similar characteristics including colour can have different streaks...which is the 'colour' the mineral makes on a scratch plate when drawn accross it in a stroke..thus creating the streak.
· decrystallization
Rub a finger over the mineral