I never thought a missing heirloom would ruin our newlywed life

im in the worst situation and dont know how to handle it since at our wedding last month my grandmothers antique bracelet went missing. Shed lent it to me as my something borrowed and I wore it during the ceremony then took it off for the reception. I left it with my mother in law for safekeeping and when I asked for it back at the end of the night she didnt have it. She swears she put it in her purse but it's not there. The bracelet is worth about $6k and has been in our family for over 100years. Now my side of the family is insinuating that someone from my husband's family took it. Theres absolutely no evidence of this but tensions are high because the bracelet is irreplaceable. My husbands family is offended by the accusations and mine is demanding we investigate. Im caught in the middle trying to keep the peace while also being devastated about losing my grandmothers bracelet. This is affecting our newlywed life because now family gatherings are awkward and there's weird tension. How do I navigate this without making things worse?? the bracelet is gone either way but the family drama is ongoing