Gemologists
you call it chemist i think
A magnetometer is a device used to measure the intensity and direction of a magnetic field.
robot
An aviologist.
scientest
You call someone that studies metal a metallurgist.
A physicist.
a person who studies planets is a planetologist.
There is no special name for someone who studies Hebrew.
An Anthropologist.
malacologist
euclidist
psychologist
A numismatist.
A Zoologist
a meteorologist.
An economist