Identifying Diamonds vs. White Topaz: Understanding Jewelry Markings

Question
is there any way to say weather a stone in the earrings real diamond or white topaz? the marking that i can read is 18K and some tooth sign, which i suppose stands for a stone, but it could mean any stone, from what i know, as i've noticed this marking before on my other jewelry. i'm not willing to pay for appraisals, but would very much appreciate advise on how to read the stone markings. this was a gift, so no way for me to ask now. if the stones were big, i would assume it's topaz, but they are small. thanks

Answer
Hi Natasha
Thank You for writing!!

The marks in your ring are makers marks to show the maker of the ring. The stones can be of any type.
To test the ID of topaz vs.Diamond we use the fol1owing tests.      1. Refractive Index test.
2. Polariscope Test.
3. Magnification Test.
4. Heat Conductivity
5. Electrical Conductivity.
6. Magnification.

These tests need to be done on the stones by a Gemologist with the proper equipment.

Arthur DeMello GG(GIA)