![24x Geometric 1920s Cardboard Science Classroom Crystal Models Early-20th century - Sold - Davidowski 24x Geometric 1920s Cardboard Science Classroom Crystal Models Early-20th century - Sold - Davidowski](https://www.davidowski.nl/galleries/24x-geometric-1920s-cardboard-science-classroom-crystal-models-early-20th-century-2506981-en-max.jpg)
24x Geometric 1920s Cardboard Science Classroom Crystal Models Early-20th century - Sold - Davidowski
![A group of fifteen Krantz-type glass crystal models, first half of the 20th century, all with colour A group of fifteen Krantz-type glass crystal models, first half of the 20th century, all with colour](https://www.tooveys.com/lots/345490/1140.jpg)
A group of fifteen Krantz-type glass crystal models, first half of the 20th century, all with colour
![Wooden crystal models from Germany or Austria, end of 19th century | Handcraft, Crystals, Displaying collections Wooden crystal models from Germany or Austria, end of 19th century | Handcraft, Crystals, Displaying collections](https://i.pinimg.com/originals/49/fb/1c/49fb1c0f07c631a9780dce6793bf8b11.jpg)
Wooden crystal models from Germany or Austria, end of 19th century | Handcraft, Crystals, Displaying collections
![File:R. J. Haüy, pearwood crystal model, collection Teylers Museum, Haarlem (the Netherlands).jpg - Wikimedia Commons File:R. J. Haüy, pearwood crystal model, collection Teylers Museum, Haarlem (the Netherlands).jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e2/R._J._Ha%C3%BCy%2C_pearwood_crystal_model%2C_collection_Teylers_Museum%2C_Haarlem_%28the_Netherlands%29.jpg/497px-R._J._Ha%C3%BCy%2C_pearwood_crystal_model%2C_collection_Teylers_Museum%2C_Haarlem_%28the_Netherlands%29.jpg)