Platinum is abbreviated Pt. and Plat. Cells of enamel are surrounded by delicate wire. A point is a hundredth of a carat or 0.002 gram. The porcelain is covered with a glassy, decorative glaze. These holes allow water, oils, and other substances to penetratethe stone, frequently changing their appearance over time.
Many stones are porous, including turquoise .
It is sometimes used for inexpensive costume jewelry. The Trifari brooch above is made of yellow glass. A princess cut is a square-cut stone. This fancy cut is relatively new and is also known as a Quadrillion or Squarillion cut. Pt. is an abbreviation for platinum .