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What is the difference between potassium feldspar sodium feldspar and calcium feldspar?
The main difference is in their chemical composition, their temperature of formation, density, colour, cleavage and mineral habit.
Calcium and Sodium Rich Feldspars:
There can be a mix of calcium and sodium (more correctly termed solid solutions) in Feldspars between Albite and Anorthite which are known generally as Plagioclase feldspars.
Depending on the relative sodium and calcium contents they are given differing names:
Albite = 100 - 90 % Na, 0 - 10 % Ca
Oligoclase = 90 - 70 % Na, 10 - 30 % Ca
Andesine = 70 - 50 % Na, 30 - 50 % Ca
Labradorite = 50 - 30 % Na, 50 - 70 % Ca
Bytownite = 30 - 10 % Ns, 70 - 90 % Ca
Anorthite = 10 - 0 % Na, 90 - 100% Ca
Alkali Feldspars (containing Potassium and Sodium)
There is also a limited solid solution series between Albite and K-Feldspars which takes the following form which is further complicated by the temperature dependent stability of some of the mineral forms:
Albite = 100 - 90 % Na, 0 - 10 % K
Anorthoclase = 90 - 64 % Na, 10 - 36 % K
Sanadine: Contains varying amounts of Na. Stable at high temperature. Occurs in rapidly cooled rocks.
Orthoclase: Predominately K, minor amounts of Na. Stable at moderate temperatures.
Microcline: Predominately K, minor amounts of Na. Stable at lowest temperatures. Common in the most slowly cooled rock types such as granites and pegmatites.
The chemical formulas of the Plagioclase Feldspars are as follows:
Albite = NaAlSi3O8
Oligoclase = (Na,Ca)(Al,Si)AlSi2O8
Andesine = NaAlSi3O8 - CaAl2Si2O8
Labradorite = (Ca,Na)Al(Al,Si)Si2O8
Bytownite = (NaSi,CaAl)AlSi2O8
Anorthite = CaAl2Si2O8
The chemical formulas of the Alkali Feldspars are as follows:
Albite = NaAlSi3O8
Anorthoclase = ((Na,K)AlSi3O8)
Sanadine = (K,Na)(Si,Al)4O8
Orthoclase and Microcline = KAlSi3O8
Colour:
Albite - White
Oligoclase - Off-white or grey or pale shades of green, yellow or brown
Andesine - White or grey
Labradorite - Grey to smoky black
Bytownite - White, grey or colourless but can be pale shades of other colours
Anorthite - White, grey or colourless
Anorthoclase - Colourless, green, grey, grey pink, yellow
Sanadine - Off-white, yellow or pale shades of other colours
Microcline - Off-white,yellowish, flesh pink, brown or green
Orthoclase - Off-white, yellow, or shades of red, orange to brown
Density (g/cm3) :
Albite - 2.61
Oligoclase - 2.64 - 2.68
Andesine - 2.68 - 2.71
Labradorite - 2.70 - 2.74
Bytownite - 2.74 - 2.76
Anorthite - 2.76
Anorthoclase - 2.57 - 2.6
Sanadine - 2.56 - 2.53
Microcline - 2.5
Orthoclase - 2.53 - 2.56
Crystal Habit:
Albite - triclinic
Oligoclase - triclinic
Andesine - triclinic
Labradorite - triclinic
Bytownite - triclinic
Anorthite - triclinic
Anorthoclase - triclinic
Sanadine - monoclinic
Microcline - triclinic
Orthoclase - monoclinic
Cleavage:
Albite - Perfect in one direction, good in second.
Oligoclase - Perfect in one direction, good in second.
Andesine - Perfect in one direction, good in second.
Labradorite - Perfect in one direction, good in second.
Bytownite - Perfect in one direction, good in second.
Anorthite - Perfect in one direction, good in second.
Anorthoclase - Perfect in one direction, good in second.
Sanadine - Good in 2 directions.
Microcline - Perfect in one direction, good in second.
Orthoclase - Good in 2 directions.
What else can I help you with?
What are the types of feldspar?
There are broadly three main types of feldspars: calcium, sodium and potassium. They have the following general chemical formulas:KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8The endmember mineral states are known as K-Feldspar, Albite and Anorthite which are the potassium, sodium and calcium feldspars respectively.There can be a mix of calcium and sodium (more correctly termed solid solutions) in Feldspars between Albite and Anorthite which are known generally as Plagioclase feldspars.For more information please see the related question
What is the scientific name for feldspar?
The scientific name for feldspar is a group name that encompasses several different minerals. The most common type of feldspar found in Earth's crust is potassium feldspar, which has the scientific name KAlSi3O8.
Is feldspar a compound or mixture?
Feldspar is a compound. It is a group of rock-forming tectosilicate minerals that are made up of aluminum, silicate, and potassium, sodium, or calcium ions.
What element makes up feldspar?
It depends on the type of feldspar. Potassium Feldspar (also called K-Spar), contains potassium, aluminum, silicate: KAlSi3O8. Plagioclase Feldspar, on the other hand, contains calcium or sodium, aluminum, and silicate: NaAlSi3O8 or CaAl2Si2O8.
What are two feldspars found in granite?
Granite contains plagioclase feldspar and potassium feldspar. It really depends on the composition of the magma from which it forms. If the granite has a lot of pink in it, chances are it is potassium feldspar (K-Spar). If it is dominated by white, then the feldspar is probably plag.
What are the types of feldspar?
There are broadly three main types of feldspars: calcium, sodium and potassium. They have the following general chemical formulas:KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8The endmember mineral states are known as K-Feldspar, Albite and Anorthite which are the potassium, sodium and calcium feldspars respectively.There can be a mix of calcium and sodium (more correctly termed solid solutions) in Feldspars between Albite and Anorthite which are known generally as Plagioclase feldspars.For more information please see the related question
What is the scientific name for feldspar?
The scientific name for feldspar is a group name that encompasses several different minerals. The most common type of feldspar found in Earth's crust is potassium feldspar, which has the scientific name KAlSi3O8.
Is feldspar a compound or mixture?
Feldspar is a compound. It is a group of rock-forming tectosilicate minerals that are made up of aluminum, silicate, and potassium, sodium, or calcium ions.
How feldspars differ from one another?
Feldspars are classified based on their chemical composition into three main groups: potassium feldspar, plagioclase feldspar, and sodium feldspar. Potassium feldspar includes orthoclase and microcline, while plagioclase feldspar includes albite, oligoclase, and labradorite. Sodium feldspar primarily consists of albite. Each type of feldspar has a unique mineral structure and varying ratios of sodium, potassium, and calcium ions.
What element makes up feldspar?
It depends on the type of feldspar. Potassium Feldspar (also called K-Spar), contains potassium, aluminum, silicate: KAlSi3O8. Plagioclase Feldspar, on the other hand, contains calcium or sodium, aluminum, and silicate: NaAlSi3O8 or CaAl2Si2O8.
What are two feldspars found in granite?
Granite contains plagioclase feldspar and potassium feldspar. It really depends on the composition of the magma from which it forms. If the granite has a lot of pink in it, chances are it is potassium feldspar (K-Spar). If it is dominated by white, then the feldspar is probably plag.
What happens when carbonic acid is mixed with feldspar?
Feldspar, a major constituent of most igneous rocks, reacts with carbonic acid to produce residual clay minerals plus dissolved ions of metals (potassium, sodium or calcium, depending on the type of feldspar). Here, for example, is the reaction by which potassium feldspar is converted to kaolinite, a clay mineral: 4KAlSi3O8 + 4H2CO3 + 2H2O → Al4Si4O10(OH)8 + 4K+ + 4HCO3- + 8SiO2 feldspar + carbonic acid + water → kaolinite + dissolved potassium and bicarbonate ions + dissolved silica Similar reactions affect sodium feldspar and calcium feldspar.
What is feldspar's chemical formula?
x Al(Al,Si)3O8, where x can be sodium (Na) and/or calcium (Ca) and/or potassium (K).
Difference between hartmann's and sodium chloride?
The Hartmannn solution contain sodium lactate and sodium, potassium, calcium chlorides.
What precipitate is produced by the reaction between calcium chloride and potassium carbonate?
The precipitate produced by the reaction between calcium chloride and potassium carbonate is calcium carbonate. When calcium chloride and potassium carbonate are mixed together, a double displacement reaction occurs, leading to the formation of calcium carbonate, which is insoluble and thus precipitates out of the solution.
Which element has larger raduis between potassium and calcium?
Potassium has the larger radius (not raduis!).
What is the difference between food and nutriants?
Food is something you eat, and nutrients are the good things that your body gets out of food like calcium or potassium
