With the increasing popularity of lab-grown synthetic opal, some companies try to confuse the market by claiming their products are same in quality. In order to protect customers' benefits, we need to provide correct information for them and prevent them from receiving false information from irresponsible companies.

What is Opal-Like Plastic?

Opal-Like plastic is a man-made opal with 20% silica and 80% resin. It is silica powder mixed into plastic and does not go through any growing process. It means that it is impossible for Opal-Like plastic to have unique vertical fire of impregnated synthetic opal. However, some companies mislead their clients by claiming that Opal-Like plastic is no different from the impregnated synthetic opal.

Feature 1:

Distinctive internal growth pattern provides the key to distinguish if a sample is impregnated synthetic opal or just mixture of plastic.

From the photo2, you can find that vertical growth pattern is absent. And the rough is commonly in round & rectangular shape.

Opal-Like plastic yellowing problem

Feature 2:

Due to it's composition of high percentage of resin, approximately 80%, Opal-Like plastic has a serious yellowing problem. However, those companies avoid mentioning about this color change problem.

This photo shows the issue of Opal-Like plastic's color change through an experiment with long exposure of lighting resembling sunlight.

To conclude, based on the comparison of chemical composition, fire pattern, rough shape, color consistency and stability, impregnated synthetic opal is a more precious material than Opal-Like plastic. We hope our illustrations above can deliver a clear picture for people who come across these man-made opals.

Two easy tips to distinguish Opal-Like Plastic:

1) Raw material looks like round or rectangular block.
2) Vertical fire which indicates grown pattern is absent. They only have pinpoint fire.

Quick Comparsion

Mineral Type
Polymer Impregnated Type
Resin Colloidal Type
Elements Nearly 100% Silica Small portion of Water 80% silica 20% resin 20% silica 80% resin
Hardness (Mohs) 5.5 4 2
Specific Gravity 1.9-2.2 1.8-1.9 1.35-1.4
Heat Resistance 900 degree C 130 degree C 130 degree C
Rough Stone Shape Irregular Irregular Round or Rectangular
Growth Pattern Yes, with vertical fire Yes, with vertical fire No, it is absent
Glass Compatibility Yes No No
Yellowing Problem No No Yes
Jewelry Plating Yes Yes No

What is opalite ?

Opalite is a clear or milky coloured iridescent glass, or sometimes even plastic, that is available in a wide range of shapes and sizes.
Sometimes Opalite is sold as Synthetic Opal, however it does not show the distinctive ‘play of colour’ of genuine opal.
It should not be confused with synthetic opal which is made of the same material as opal (silica) and still has the same play of colour as natural precious opal.
Opalite is a cheap man made material as they are simply glass or plastic.


The photo of opalite:

Opalite is with milky color and do not have the play of color effect.