The relative lengths of the crystallographic axes is a very important feature of all crystals except those of the isometric system in which the axes are always of equal length so that the ratio is 1:1:1.
There are three noninterchangeable crystallographic axes at right angles.
To bring out the relations of the faces of a crystal and further aid in classification, prominent, straight lines or directions passing through the center of a crystal are chosen as crystallographic axes.
Many crystals outside the isometric system also exhibit a remarkable tendency to absorb light differently in different crystallographic directions, thus producing two or three color tints, which vary according to the substance.
Characterized by three crystallographic axes at right angles to each other, only two of them interchangeable.
Characterized by four crystallographic axes, one vertical and three interchangeable horizontal axes making angles of 60 degrees with each other.
Basing our definitions upon both symmetry axes and crystallographic axes, the seven systems are as follows: 1.
There are three noninterchangeable crystallographic axes, only two of which are at right angles.
The term allotropy has also been applied to inorganic compounds, identical in composition, but assuming different crystallographic forms.
Mitscherlich, who also observed the similarity of the crystallographic characters of selenates and sulphates, which afforded valuable corroboration of his doctrine of isomorphism.
A crystal may be regarded as built up of primitive parallelepipeda, the edges of which are in the ratio of the crystallographic axes, and the angles the axial angles of the crystals.
The relation mentioned above between the crystallographic constants and the chemical composition is unique amongst minerals, and is known as a morphotropic relation.
About the same time, from the Breitenbach meteorite were extracted crystals of Bronzite, which yielded the first crystallographic elements obtained for that mineral: the measurements were made and published by Dr.
The simplest and commonest form of this group is the quadratic octahedron, the ground-form of the quadratic crystallographic system; its equatorial plane is a square.
The simplest and commonest form of this group is the rhombic octahedron, which is also the ground-form of the rhombic crystallographic system.
Optically biaxial crystals in which the three principal optical directions coincide with the three crystallographic axes--corresponding with the orthorhombic system.
There are only three dyad axes of symmetry, which coincide with the crystallographic axes; in addition there are three triad axes and a centre of symmetry.
The isothermal surface in a uniaxial crystal is therefore a spheroid; in cubic crystals it is a sphere; and in biaxial crystals an ellipsoid, the three axes of which coincide, in orthorhombic crystals, with the crystallographic axes.
The optical orientation of an orthorhombic crystal is completely defined by stating to which crystallographic planes the optic axial plane and the acute bisectrix are respectively parallel and perpendicular.
Examined in parallel light between crossed nicols, such a crystal extinguishes parallel to the crystallographic axes, which are often parallel to the edges of a face or section; there is thus usually "straight extinction.
In orthorhombic crystals the three principal vibration-directions coincide with the three crystallographic axes, and have therefore fixed positions in the crystal, which are the same for light of all colours and at all temperatures.
The ultimate aim ofcrystallographic research is to determine the internal structure of crystals from both physical and chemical data.
Optically biaxial crystals in which only one of the three principal optical directions coincides with a crystallographic axis--corresponding with the monoclinic system.
In anorthic crystals there is no relation between the optical andcrystallographic directions, and the exact determination of the optical orientation is often a matter of considerable difficulty.
In the cubic system, for example, the three crystallographic axes are taken parallel to the three tetrad axes of symmetry, i.
Its crystallographic features are well described by the Rev.
This has been done for hemoglobins of the blood by Reichert and Brown, who have shown by crystallographic measurements that the hemoglobins of any species are definite substances for that species.
But the formation of the halo is not, at least in its earlier stages, attended by destruction of the crystallographic and optical properties of the medium.
Brooke, owed its chief value to a mass of crystallographic observations which he had made with his usual accuracy and patience during many years, and there tabulated in his concise manner.
Tutton draws the general conclusion that the crystallographic properties of the isomorphic rhombic sulphates R{2}SO{4} are a function of the atomic weight of the metals contained in them (see Chapter XV.
Note: In uniaxial crystals, the optic axis has the direction of the vertical crystallographic axis.
Defn: The combination of planes included under a general crystallographic symbol.
Defn: The ratio of the three crystallographic axes which determines the position of any plane; also, the fundamental axial ratio for a given species.
The combination of planes included under a general crystallographic symbol.
The ratio of the three crystallographic axes which determines the position of any plane; also, the fundamental axial ratio for a given species.
This has been done for hemoglobins of the blood by Reichert and Brown,[54] who have shown by crystallographic measurements that the hemoglobins of any species are definite substances for that species.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "crystallographic" in a variety of sentences. We hope that you will now be able to make sentences using this word.
