I sold some vintage ivory pieces that my brother brought home in the 50s. Four out of five dealers tried to steal them, or were lacking in expertise, by telling me that they were bone, ivorine, pressed ivory powder etc. It was fun when they didn't know I was a dealer and also knew the exact origin. Beware of unscrupulous and ignorant dealers. Ivory has a grain, is extremely hard, always cracks from the base up and darkens with age. When you press a hot pin against it, the pin will not penetrate and it will smell like burnt hair or a singed fingernail. All Ivory has value if it is antique as it is illegal to sell new ivory. Only an expert can determine if it is true Dynasty art or tourist trade goods and tell you its value. Mine were 6 inch Japanese deities, not rare but well done and they brought good money. 125.00 for 7 back in 1980. Today I would expect about twice that.
I hope that helps.
I am not implying Ipcress is one of those dealers. I just edited this when I saw the post.