What is a solid solution in phase diagram?
What is a solid solution in phase diagram?
A solid solution describes a family of materials which have a range of compositions (e.g. AxB1−x) and a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. Solid in which components are compatible and form a unique phase.
Is plagioclase a solid solution?
Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more properly known as the plagioclase feldspar series.
Is feldspar a solid solution?
Feldspars are aluminosilicates, containing silicon and aluminum ions bound together by oxygen ions to form a three dimensional framework of atoms. There is little solid solution between alkali feldspars (contain potassium (K) +/- sodium (Na)) and anorthite ( contains Na and or Ca).
What feldspar mineral is an example of solid solution?
Plagioclase is the name of a group of feldspar minerals that form a solid solution series ranging from pure albite, Na(AlSi3O8), to pure anorthite, Ca(Al2Si2O8).
What is a solid solution in geology?
A solid solution series is the compositional range between end-member minerals that share the same basic chemical formula but experience substitution of elements in one or more atomic sites. For example, iron and magnesium can readily replace one another in a mineral.
What is a solid solution alloy?
a mixture of metals, which form a single phase system and in which the atoms are scattered randomly throughout the crystal structure (space lattice). Metals are miscible in the liquid state and remain completely mixed on solidification. Synonym(s): solid solution alloy.
Is plagioclase vitreous feldspar?
Feldspars have vitreous lusters and occur in opaque shades of white to gray to pink to very dark gray. Other rarer colors are also possible! The feldspars are divided into two main groups: Potassium feldspar (“K-spar”) and plagioclase (“plag”).
What type of rock is plagioclase?
igneous rocks
Plagioclase is found in almost all igneous rocks and most metamorphic rocks, but is less common in sedimentary rocks where it usually weathers to clay minerals or a fine grained variant of muscovite (sericite).
Is plagioclase a type of feldspar?
All minerals in this grouping have the same crystalline structure. The feldspar group has nearly 20 recognized members, but only nine of those are common. These may be divided into two types of feldspar: plagioclase and alkali.
Does plagioclase have fracture?
Both plagioclase and K-spar are commonly white; the lack of striations suggests that this is K-spar. The salmon-pink color is typical of K-spar. Note the two cleavage surfaces and one fracture surface. There are no striations.
What is solid in solid solution?
solid solution, mixture of two crystalline solids that coexist as a new crystalline solid, or crystal lattice. The substances may be soluble over a partial or even complete range of relative concentrations, producing a crystal whose properties vary continuously over the range.
What is binary solid solution?
Solid Solutions One of the simplest binary phase diagrams is one in which both components are completely miscible in each other in all proportions, forming a solid solution. Examples include metals which form alloys and many mineral systems.
What is plagioclase feldspar series?
Plagioclase is a continuous series of solid solutions known as the plagioclase feldspar series, rather than a specific mineral with a particular chemical composition. The series ranges from albite to anorthite endmembers (with respective compositions NaAlSi3O8 to CaAl2Si2O8), where sodium and calcium atoms can substitute for each other in
What is the classification of feldspar?
Feldspar mineral classification: This ternary diagram shows how feldspar minerals are classified on the basis of their chemical composition. The sequence of minerals along the left side of the triangle represents the solid solution series of the alkali feldspars. The sequence along the base is the solid solution series of the plagioclase feldspars.
What type of solution is plagioclase?
Plagioclase. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more properly known as the plagioclase feldspar series (from the Ancient Greek for “oblique fracture”, in reference to its two cleavage angles). This was first shown by the German mineralogist Johann…
What is the deflection angle of feldspar?
The deflection angle is an optical characteristic and varies according to the albite fraction (Ab). There are several plagioclase feldspars in the series between albite and anorthite. This diagram shows how feldspar minerals are classified on the basis of their chemical composition.
