Rare Pre-1941 Mammoth Cave Souvenir Crystal Onyx Mineral Specimen. Purchases at estate sale. I assume it probably pre-dates 1941 when Mammoth Cave was made a National Park since it is unlawful to remove natural items from all National Parks. However, it could be from the 1950s or 60s but certainly not any newer.

Approximately 5-1/4" tall embedded on 4-1/2" x 4-1/4" concrete base. Weighs over 4 lbs.