Geometrich punchmark, consisting of an tourine symbol surrounded by semi-circles and circles / Blank. 12mmx10mm, 1.42 grams. Probably struck in Ujjain. Rajgor series 23 (unlisted type - this is the only coin of this type I have seen).
These coins are usuall described as "1/2 karshapanas" and listed as such in various catalogues. However, a weight of a 1/2 karshapana should be 1.7 grams (8 mashakas), while the weight of these coins average about 1.3 grams (6 mashakas). Thus it is very unlikely that these coins were struck to a karshapana standard, but to an earlier and more obscure 6-mashaka standard.
Avanti was an ancient Indian janapada (realm), roughly corresponded to the present day Malwa region, with the great city of Ujjain (also known as "Avanti") as its' capital. According to the Buddhist text, the Anguttara Nikaya, Avanti was one of the solasa mahajanapadas (sixteen great realms) of the 6th century BCE. The janapada was divided into two parts by the Vindhyas, the northern part had its capital at Ujjayini and the southern part had its centre at Mahishmati. The Kingdom remained independent until about 403 BC, when it was conquered by Emperor Sisunaga (Shishunaga) of The Magadha Empire.