These geometric crystal shapes are very much collectable and these black Bakelite ones are the holy grail. There are four octahedrons, one flattened cube, and a 10 sided diamond. Large diamond shape 31 cm long.
Flatten square 19 cm x 16 cm. Octahedron 22 cm x 14 cm. They would have been used to either teach solid geometry and the formation of crystals or to help art students with geometric shape visualization.
No longer used in school they now make fantastic decorative items. They are all in good condition, there are a few chips and nibbles. Obviously this item is not new, it has been used in classrooms so there may be some cosmetic wear. This item is in the category "Antiques\Science/Medicine\Scientific Instruments". The seller is "barrie5757" and is located in this country: GB. This item can be shipped to United Kingdom, Austria, Belgium, Bulgaria, Croatia, Republic of, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Australia, United States, Bahrain, Canada, Brazil, Japan, New Zealand, China, Israel, Hong Kong, Norway, Indonesia, Malaysia, Mexico, Singapore, Korea, South, Switzerland, Taiwan, Thailand, Bangladesh, Bermuda, Bolivia, Barbados, Brunei Darussalam, Cayman Islands, Ecuador, Egypt, Guernsey, Gibraltar, Guadeloupe, French Guiana, Iceland, Jersey, Jordan, Cambodia, Liechtenstein, Sri Lanka, Macau, Monaco, Maldives, Martinique, Nicaragua, Oman, Pakistan, Peru, Paraguay, Reunion, Saudi Arabia, South Africa, United Arab Emirates, Chile, Bahamas, Colombia, Costa Rica, Guatemala, Honduras, Jamaica, Kuwait, Panama, Philippines, Qatar, Trinidad and Tobago, Uruguay, Vietnam.