This is a pure Sindhi tradition, where each woman used to wear it.
Sindh is a large province of Pakistan.
TOQ is decorated with beautiful and precious stones.
This type of necklaces has always been used by many Gypsies or Kochi people (Indian, Afghani, Pakistani, Turkmani and Iranian gypsy people.)
This design resembles a lot with the TOQ used in deserts areas, such as Thar, Thal, Cholistan, Rajasthan etc.
This TOQ is designed very differently from normally used TOQ as the desert areas are usually very hot.
So such designs usually made in order to increase the beauty of their neck.