News Excerpt:
Archaeologists have discovered a remarkably unusual cache of 2000-year-old coins within the remains of a Buddhist shrine at Mohenjo-Daro in Pakistan.

About the news:

• The coins and the stupa are expected to belong to the Kushan Empire, a mainly Buddhist polity.
• The Kushanas ruled from about the second century B.C. until the third century A.D. and controlled a large territory ranging from the Aral Sea through areas including present-day Uzbekistan, Afghanistan, and Pakistan into northern India.
• They also conquered the Greco-Bactrian kingdom established in Central Asia by Alexander the Great.

Reason for the Green color of coins:

These coins are made of copper. When copper is exposed to air in the presence of moisture, it leads to corrosion. This process over time leads to copper turning greenish. (Corrosion refers to the process of slow deterioration of metals)

About Mohenjo-Daro:

• This site contains the remnants of one of the oldest civilizations, i.e. Indus Civilization.
• It is the largest city on the right bank of the Indus River, while Rakhigarhi is the largest city of the Indus Valley civilisation.
• The name “Mohenjo-daro” literally means “the mound of the dead” in the local Sindhi language. 
• Like other Indus sites, Mohenjo-Daro also boasts of elaborate town planning, 90-degree street grids, a developed drainage system, as well as monumental buildings such as the Great Granary and the Great Bath.
• It was designated a UNESCO World Heritage site in 1980