Crystal drawing is a type of representation that is aesthetically pleasing and also conveys information which is less accurate compared to either gnomonic or stereographic projection about crystals symmetry. The drawings usually convey crystal’s corners and edges projected onto a plane. Like many scientific drawings, crystal drawings are not true perspective drawings but are treated as a parallel projection as if the rays proceeding from corners and edges are parallel to the eyes of the viewers’.
Crystals on the drawings are drawn accurately to scale using clinometric or clinographic projection which is a slightly inclined form of parallel perspective. By locating the eyes to an infinite distance, parallel lines can remain parallel instead of converging to a vanishing point as in perspective drawings. The drawing method foreshortens the appearance of the crystal from front to back, but it still conveys the lengths and angles of crystals.
The standard position developed over time and implemented almost universally in the late nineteenth century is to draw the crystal as if it were rotated 18◦ 26’ to the left and inclined 9◦ 28’ forwards. The designation “clinometric ” or “clinographic” refers to this fact. The slight rotation distinguishes the method from the orthometric or orthogonal projection, which represents the crystal as seen directly from above, as in a plan, or from the front, as in an elevation, a plane of symmetry being usually the plane of projection.
The projections of crystals are a means of conveying crystallographical information in a two-dimensional printed form. Stereographic and gnomonic projections are useful to crystallographers for describing a crystal exactly. To show the look of a crystal in various publications, the techniques of crystal drawing were devised, and the art of crystal representation developed over the course of centuries like the history of the science itself.(Schuh, 433)
Wentzel Jamitzer(1598–1586) a leading member of German goldsmiths and engravers supplied an early masterwork of the geometric design showing in the elaborate renderings. 140 simple to complex shapes of tetrahedron, octahedron, cube, dodecahedron, and icosahedron were drawn by replacing edges and angles with one or more planes.
Anselmus Boetius de Boodt’s work is an example of a treatise on mineral substances that departs from an alphabetical arrangement in presenting its description of stones describing minerals that are more detailed, more extensive, more critical and more systematic than many earlier works.
Nicolaus Steno in his notable De Solido Intra Soldum Naturaliter Contento Dissertationis Prodromus (1669) described various gems, minerals, and fossils enclosed within solid rocks. Steno illustrated cross sections of quartz crystal which was an important discovery that interfacial angles of quartz crystals are always the same.
Hottinger Die Krystallologia (1698) At the age of 18 makes observations on crystal habit and concludes that crystals grew from solution.
Moritz Anton Cappeller published his Prodromus Crystallographiæ de Crystallis in 1723. Cappeller concluded that a small set of basic crystal forms existed.
John Hill [c1707–1775] in his Natural History of Fossils of 1748 shows minerals in their idealized form while Antoine Joseph Dezallier d’Argenville [1680–1765] includes engravings of quartz specimens in his L’Historie Naturelle Eclaircie dans une de ses Parties Principales, l’Oryctologie of 1755 which are representations of the crystals as they would be found in nature.
Linneaus and Rome de I’sle both attempted to give the indication of three-dimensional form to the crystal drawings by the use of diagram shading.
Rene used dashed lines to indicate the hidden faces his type of diagram conveys to the viewer a great deal about the crystal shape, and is better than the shading eﬀects of the previous works. It quickly became a standard type of crystal illustration.
Beudant tried to distinguish primary and secondary forms of crystal by coloring with pastels to emphasize the contrast.
Dana, Naumann Continued to use the convention of clinogrpahy in their pulblications.
Crystal drawings from Philip’s Mineralogy 1852 are drawn in orthagonal projections which fails to render the inclination of the faces and edges and lack the apearance of solidity.
Koksharov purposely selected his material base on the complexity of the forms creating beautiful drawings
By the end of the nineteenth century, many of the publications had chapters introducing the procedures for drawing crystals. Lewis describes the techniques to render crystal forms in two dimensions.
No matter how eloquent and accurate the description, illustrations can never be replaced for presenting information to the reader. Conversely, an illustration of a crystal can never convey the sense of density, feel, smell.
- Schuh, Curtis (2007) Mineralogy & Crystallography: On the history of these sciences from beginnings through 1919. Tucson, Arizona