1.Appearance
First look hot drilling cutting surface, cutting surface, the higher his diopter, better brightness, and secondly, the cutting surface is uniform, there is gnashing of teeth, scratches, bubbles are deemed defective. Hot drilling process demanding, complex process, the yield is not very high, the defect rate of 3% -5% of the diamonds should be regarded as a good product, and then look at the size of the diamond are the same. SS6 numbers in diameter 1.9-2.1mm, SS10 numbers in 2.7-2.9mm .... Also should look at the thickness is consistent.
2.Adhesive
Look at the color of diamonds over the back of gum, the color is uniform, not shades. Brightly colored uniform, seen as a good diamond.
3.Firm
Rhinestone glue on the back of higher solubility, fastness diamonds as possible. The best way to identify diamonds: hot on the washing machine after a good wash, washing can not afford to prove fastness, washed it off, not to prove firmness of glue, a good product does not dry out.
Common grade
Common Korea hot drilling into special A grade, A grade, B grade. Three levels.
Special Class A: high brightness, no variegated drilling, even cutting surface, without teeth, scratches, bubbles, defective rate of 1% -2%, unglued end probability of 0.5% to 1%, the diamond the same size, firm high.
Class A: brightness, there are few variegated diamond cutting surface uneven teeth, scratches, bubbles, defective rate of 5% -8%, unglued end probability of 1% -2%, consistent with the size of the diamond, strong high.
Class B: brightness difference, with 15% noise drill. Uneven cutting surface, multi-tooth, scratches, bubbles, defective rate of 20% -50% chance of unglued bottom 3% to 10% the size of the diamond is inconsistent, low firmness.
