The financial crisis has had a significant impact on Bulgaria's aggregates sector but a new association for the sector is giving it a renewed focus. Julie-Anne Ryan reports. It is a well-known fact that Switzerland does not have a wide range of raw material resources suitable for extraction. No lignite, gold or petroleum are mined or produced on Swiss territory. On the other hand, Switzerland is "rich in rocks," said André Renggli, who is president of the Association of the Swiss Aggregate and Concrete Indu