The term 'classic' certainly applies to the famous interpenetration Fluorite twins from England, including those from this well-known North Pennines mine (formerly named the Beaumont Mine). These lustrous and gemmy Fluorites have good purple color, and sparkly preferential coatings of lustrous Quartz crystals. The exemplary, large crystal is 2.7 cm, and it is zoned (evident when you look at the incredible fluorescence). ex. AK Borland collection, probably from the 1970's. Excellent and classic.