Marble (toy) conventions. Additionally, many glass artisans produce art marbles for the collectors' market only, with some selling for thousands of dollars. Marbles are made using many techniques. They can be categorized into two general types: hand-made and machine-made. Marbles were originally made by hand. Stone or ivory marbles can be fashioned by grinding. Clay, pottery, ceramic, or porcelain marbles can be made by rolling the material into a ball, and then letting dry, or firing, and then can be left natural, painted, or glazed. Clay marbles, also known as "crock marbles" or "commies" ("common"), are made of slightly porous clay, traditionally
Elgin Marbles "As with anything stolen or taken from occupied or colonial possession – including artefacts looted from other countries in the past – we should be engaged in constructive talks with the Greek government about returning the sculptures." Following the 2016 United Kingdom European Union membership referendum, it has been suggested that the United Kingdom may be forced to return the marbles to Greece as a precondition for an agreement on Brexit, as any agreement between the European Union and the United Kingdom has to be approved by European Union member Greece. Elgin Marbles The Elgin Marbles (), also known as