1. a blue-gray sandstone used for building and paving
2. copper sulfate, especially when used as a fungicide or algicide
Usage: chemistry

Examples

• The old church was built with local bluestone quarried from nearby hills.
• Workers laid bluestone pavers to create an elegant walkway.
• The historic courthouse features beautiful bluestone steps.
• Farmers use bluestone to treat fungal diseases in their crops.
• The swimming pool was treated with bluestone to prevent algae growth.
• Bluestone sidewalks are common in many northeastern cities.