A halo is like a push up bra for a diamond it ll make the stone look a carat to a carat and a half larger than it actually is.
What a real diamond looks like.
If the stone s mounting appears to be plated or is only a semi precious metal like copper or aluminum the diamond itself may be fake.
Place the glass on a table or any platform and use your diamond to scratch the surface of the glass.
If the fog dissipates right away the diamond is real.
Something like a scratch test could help you determine if the diamond under the question is in fact real.
A light fog will form on the diamond because of the moisture and heat in your breath.
In the chart below you ll find common diamond look alike stones and real diamonds arranged by specific.
However two properties specific gravity and birefringence hold the key to distinguishing diamonds.
Most diamonds are set in a precious metal like gold or platinum.
Diamonds and their simulants can share some optical and physical properties.
For you to go through with the scratch test you need a plate glass and a loose diamond.
Similarly if the setting looks sloppy or like poor quality craftsmanship the diamond may not be particularly valuable.
If you want to make your diamond look bigger either set your diamond with side stones or with a halo says landau.