The Roman government stopped coining in silver primarily due to economic and political factors. During the late Roman Republic and early Roman Empire, silver was the preferred metal for coinage. However, as the empire expanded and faced various challenges, the government had to adapt its fiscal policies to sustain its vast territories and military campaigns. The shift in coinage metal from silver to other cheaper metals, such as bronze and copper, was one of the strategies employed by the Roman government to address these issues.

Economic Factors:
1. Inflation: The continuous debasement of silver coins led to inflation, as the value of the currency decreased. This practice began during the reign of Emperor Nero and continued over time, resulting in a loss of trust in the currency.
2. Economic Crisis: The Roman Empire faced several economic crises, including a decline in agricultural production, a decrease in trade, and a rise in unemployment. These factors contributed to a shortage of silver and made it economically unviable to continue using it for coinage.

Political Factors:
1. Military Expenses: The expansion of the Roman Empire required vast financial resources to support the military campaigns, maintain infrastructure, and administer the immense territories. The cost of these endeavors put significant strain on the imperial treasury, making it necessary to find alternatives to expensive silver coinage.
2. Tax Collection: The Roman government relied heavily on taxes to finance its operations. By using cheaper metals for coinage, the government could produce more coins and collect higher taxes, easing the fiscal burden.

Transition to Other Metals:
1. Bronze and Copper: The Roman government shifted to using bronze and copper for coinage. These metals were more abundant and less expensive than silver, making them suitable for mass production.
2. Base Metal Coinage: With time, the Roman government introduced base metal coinage, such as the Antoninianus, which contained a small percentage of silver but was mostly made of base metals like copper or bronze. This allowed the government to maintain the appearance of a silver coin while reducing costs.
3. Monetary Reform: The transition to base metal coinage was accompanied by various monetary reforms aimed at stabilizing the currency and restoring trust in the Roman economy. However, despite these efforts, the debasement of the currency continued, ultimately contributing to the decline of the Roman Empire.

In conclusion, the Roman government stopped coining in silver due to economic challenges, including inflation and economic crises, as well as the need to sustain the expanding empire and finance military campaigns. This led to the use of cheaper metals like bronze and copper for coinage, which ultimately contributed to the debasement of the currency and the decline of the empire.

Roman government stopped coining silver bcoz of scarcity of silver and begin to use gold coins that is known as solidus.