29. The Craft of Bidriware: Zinc-Copper Alloy Metallurgy and GI Protection

Structural Mechanics

Bidriware is a traditional metal handicraft from Bidar, Karnataka, protected under GI status. The craft utilizes a unique, dark-colored zinc-copper alloy base, which is hand-engraved with pure silver wires or sheets. The blackened color of the alloy is achieved by applying a paste made from soil collected from the ruins of the Bidar Fort, which contains specific ammonium chloride and nitrate mineral concentrations. The craft faces economic challenges, including zinc price volatility and structural constraints in artisan training.

Data-Driven Metrics

• Alloy Ratio: Authentic Bidriware uses a zinc-to-copper alloy ratio of approximately 16:1, ensuring a lightweight base that accepts detailed silver inlay work.
• Chemical Reaction: The Bidar Fort soil paste reacts with the zinc base to create a deep, durable black finish, while leaving the inlaid silver unaffected.
• Cluster Contraction: The active Bidri artisan pool has contracted due to rising raw material prices and competition from imitation zinc-plated plastics.

Strategic Vector

The Department of Mines and Metallurgy should establish a dedicated raw-material supply depot in Bidar, providing copper, zinc, and silver inputs to GI-registered artisans at wholesale market rates.