


Early Crystal Models
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Wooden model illustrating Haüy's laws of decrement on the edges
France, early 19th century (height 5.5 cm)
The model represents Haüy's theory of how the dodecahedron with pentagonal faces (pyritohedron) is constructed from a cubic nucleus by decrement of two rows of "integrant cubic molecules" of each newly added layer on two opposite edges combined with a decrement of only one row of molecules on every two successive layers on the other two edges. This combination takes place in three perpendicular directions.
The model whose edges show 17 cubic "molecules" fits exactly the illustration in the atlas of Haüy's "Traité De Minéralogie" (1801).


Wooden
model illustrating Haüy's laws of decrement on the edges and vertices
France, early 19th century (height 7 cm)
The model illustrates a complex differential decrement
of cubic "molecules" on the edges AND on the vertices. It
results from a combination of Haüy's laws giving
the octahedron starting from the cube combined with that
giving the pyritohedron and exemplifies crystal forms
of pyrite ("sulfure de fer icosaèdre" of Haüy).
Haüy R.J. Annales de Chimie, 17, 225319 (1793).


P.
Groth & F. Krantz collection (1880)
Wooden crystal models (ca. 3.5 to 5.5 cm) from the P.
Groth & F. Krantz collection (1880)
6 silver and/or goldcontaining minerals. From left to
right:
top row: stephanite (392), krennerite (394), hessite (47)
bottom row: sylvanite (533), proustite (215) and freislebenite
(539). 

F.
Krantz glass crystal model (ca. 1900?)
Glass model of a monoclinic crystal (ca. 20 cm) from a
series.
A small glued label indicates: "I  Dr. F. Krantz  Bonn
a. Rh."
Internal silk threads materialize the crystallographic
axes and illustrate with the corresponding colours the
dispersion of the optic axes and of the acute bisectrix
for blue, yellow and red light. 

F. Krantz wooden crystal model of an hexoctahedron
Large (16,5 cm high) hollow wooden model of an hexoctahedron {321} stamped "7" from a series of 30. Large models of this type (1525 cm) were furnished for demonstration purposes. Two slightly different sets are described in the second and third editions of Krantz’s catalogue n° 18. First half 20th century.


P.
Groth & F. Krantz collection (1880)
5 rotatable wooden models of twin crystals (ca. 5.5 to
7.5 cm) from the P. Groth & F. Krantz collection (1880)
From left to right:
top row: gypsum (564), lazulite (589)
center: trydymite (711)
bottom row: titanite (702), calcite (307) 

Porcelain
crystal models (ca. 1841)
Collection of 24 cream colored biscuit porcelain crystal
models (size ranging from 3 to 10 cm) in contemporary
(but probably not original) mahogany case. Each has faces
stamped P, M and T and most models are identified in manuscript
on paper labels.
The models are not signed, but the material they are made
of and the stamped letters P, M, T are typical for models
made by John Joseph Griffin (ca. 1841) 

Colored
glass crystal models
24 colored glass crystal models (size ranging from 1.5
to 5 cm) in chamoisleather and plush lined leather covered
case (36.5 x 22.2 x 5 cm).
Unsigned, first half 20th century. 

Colored
glass crystal models
20 colored glass crystal models (size ranging from 1.5 to 3.1 cm) in chamoisleather lined, plush soft fabric covered inner lid. Faux leather case (21.5 x 15.5 x 3.2 cm).
Unsigned, likely Czechoslovakia, late 19th early 20th century.


F.
Krantz glass crystal model
Glass models of a hexagonal and tetragonal crystal from
a series. The height of the hexagonal prism is 14.8 cm,
the height of the tetragonal bipyramid is 20.2 cm.
Internal silk threads materialize the crystallographic
axes; red for the caxis, yellow for the other axes.
On the tetragonal crystal model a small glued label indicates: "16  Dr. F. Krantz  Bonn
a. Rh." On the hexagonal crystal there is a similar label indicating: "10  Dr. F. Krantz  Bonn
a. Rh.", and another gilded label with the Krantz logo and the text "Dr. F. Krantz  Bonn am Rhein".
Both models,
first half 20th century. 

F. Krantz cardboard crystal model
Cardboard model (25 x 10 cm) of a tourmaline crystal from a series of 60. These models were offered varnished to prevent damage.
A small glued label indicates: "25  Dr. F. Krantz  Bonn a. Rh.", first half 20th century.


Set of Bakelite crystal models
unsigned set of 14 black models with white edges. Dimensions of the models are given below each photograph
First half 20th century. 

19th century glass and wire model
Glass cube, edge 66 mm. Inside the cube, 9 cubic crystal forms delineated by colored wires are present; three 6faced, five 24faced and one 48faced models. The model comes in a red plush lined mahogany case.
The maker is unknown.


Case with wooden crystal models
Collection of 36 maple and fruit wood crystal and geometric
models (size ranging from 3 to 4 cm) in paper covered
wooden case (22.5 x 19 x 6 cm). The sliding lid of the
case is covered with a colored lithograph depicting a
teacher with two students studying a collection of crystal
models. Text on the lithograph "Krijstallographie.
 Crystallographie, Crystallography". The box also
contains a paper (41.7 x 33.8 cm, folded twice to fit
in the case) with 8 unfoldings to make paper crystal models.
Ca. 1860. 

Wooden models of twinned feldspar crystals
18 rotatable wooden models of twinned feldspar crystals (all ~2.7 x 2.2 cm) with face symbols in brown ink in a grayish paper covered cardboard box (19.5 x 10.1 x 1.6 cm).
G.E. Kayser, Berlin, 1834.
On the occasion of his inauguration in 1834, Gustaf Eduard Kayser (1803?) presented this set of wooden crystals to Christian Samuel Weiss (17801856) who was professor at the University of Berlin.


Case with wooden crystal models
15 wooden crystal models (average size 5 cm) in wooden case (34 x 25 x 6 cm). Each crystal model bears a number that corresponds to a printed list on the inside of the lid.
Unsigned, mid 20th century.


Wooden crystal models from Germany or Austria
A collection of 135 (some duplicates) wooden crystal models  6 with movable parts  used for teaching purposes during 20th century: 66 models are mounted on black painted wooden bases (47 with their original labels) while 69 models are unmounted; maximum height of the models including the base: 9 cm
82 loose wooden bases (most of them with a label) are also present. The back of two detached labels bears "K. K. Staatsgymnasium Wien I."
End 19th century




