Ceramic classification

Ceramic containers come in a vast array of shapes; shapes may have had specific uses, while others may have served many purposes. In Ponda.org, the types of vessels are not based on the presumed use of a vessel, nor do they indicate what these uses may have been. On the contrary, it is a purley descriptive system based for the most part on the ratio between maximum diameter and height, and on the ratio between maximum and rim diameters. In this we largely follow Harmann (2016).

The ratio between maximum diameter and height gives the Vessel Index (Vi = Max. diam. / Height x 100). All vessels with a Vi  greater than 160 belong to the Bowls category; vessels with a Vi smaller than 160 that are either open or restricted belong to the Beakers category; vessels with a Vi smaller than 160 that are closed belong either to the Jars or Bottles categories.

The ratio between the maximum and rim diameters gives the Opening Index (Oi = Rim diam. / Max. diam. x 100).  All vessels with an Oi of 100 are considered open; vessels with an Oi between 90 and 100 are considered restricted; vessels with an Oi smaller than 90 are considered closed.

This system is partly based on the availability of secure measurments, which are unfortunately not always available. However, these ratios can sometimes be determined from a good side photograph or drawing. To add to the complexity of the system, some containers were given fancy shapes, such zoomorphic vessels, boxes, rattles, joint multiples vessels, etc.

In the graphics below, you can see the current classification system, with references to Hartmann's shapes.