This is a Fossil Mammoth Ivory, time period is the Ice Age and was found in Suwannee River, Florida. This piece is polished via a natural river polish.  This piece measures approx 58 x 36 mm: thickness is 13 mm: weight is 41 grams ($30).  Second piece measures approx 46 x 30 mm: thickness is approx 12: weight is 13 grams ($25).
 
An Ice Age  is a glacial episode during a past geological period. The most recent Ice age being, 115,000 to 11,700 years ago.