Hi,
You have a beautiful and old jambiya.
It's not a Meccan jambiya.
So-called Meccan jambiya... I have to take care or someone will open a thread "the Meccan jambiya the weapon that never existed"...
You have an Assib abdi style jambiya from the Hadhramawt.
Maybe collected in Aden or Shihr.
You should post a good photo of the hilt.
It might be ivory, but also rhino or amber... it's difficult to see from a distance...
Do you have an Arabic inscription on the scabbard, just above the knot?
For the date I will say around 1900 (1880-1920).
Lucky you
Kubur