Two Chinese characters Ban Liang ("Half an ounce"), no rims or other marks / Blank, no rims. 30mm, 6.59 grams. Gratzer/Fishman "The Early Round Coins of China" #12.5; Hartill #7.7. 

Standardized issue of Huangdi. These large heavy coins are popular and rare.

A Chinese ounce (liang) weighs about 16 grams. The earliest "Ban Liangs" weighed around 5 to 20 grams, with the weight fluctuating over this wide range. Emperor Shi Huangdi introduced monetary reforms, fixing the weight around 8 grams - The "History of Han" says: When Qin united the world, it made ...[the currency] of bronze, which was similar to the coins of Zhou but bore an inscription Ban Liang ("Half Ounce") and was equal in weight to its inscription. These Qin dynasty coins are large, impressive, rare and very popular.

Qin Shi Huangdi (259 BC - 210 BC) was king of the Chinese State of Qin from 246 BC to 221 BC during the Warring States Period. He became the first emperor of a unified China in 221 BC. He ruled until his death in 210 BC at the age of 50. Qin Shi Huang is a pivotal figure in Chinese history. After unifying China, he and his chief advisor Li Si passed a series of major economic and political reforms. He undertook gigantic projects, including the first version of the Great Wall of China, the now famous city-sized mausoleum guarded by a life-sized Terracotta Army, and a massive national road system, all at the expense of numerous lives.

This coin is unconditionally guaranteed to be authentic.