Video: Rock of the Day – Maurizio Napoli on porphyries July 1, 2019November 5, 2020 by Spotlight Mining Team Maurizio Napoli (VP Exploration, Crystal Lake Mining) shows us the differences between a regular and a potentially mineralised porphyry outcrop sample. Originally published to CLM’s social media channels: June 2019 https://www.youtube.com/watch?v=jawq5EezoGI