Tips on Buying Gemstones
Generally, the price of any gemstone is determined by: size,
cut, quality (color/clarity/treatments), and type. Here are
some questions to ask about quality:
- Has it been treated?
- Is the stone natural or synthetic?
- Are there any noticeable scratches, chips or
- Is the color even throughout the stone?
- How good is the color?
- If you are buying the stones for earrings or
cufflinks, are the stones well matched?
There are many ways that dealers treat gemstones. The savvy
buyer asks lots of questions and hopefully tests the results.
Here are some treatments to look for:
It is common to irradiate Aquamarine, London Blue Topaz,
Emerald, and Diamond as well as other stones. This treatment
brings out color and removes imperfections. Many dealers know
if the stones they are selling have been irradiated. Honest
ones will tell you if they are aware of the treatment.
Amethyst, Aquamarine, Ruby,
Tanzanite and Topaz are often heated at high temperatures to
This is the most common treatment used. On clear stones, dye
may be visible in cracks that are darker than the rest of the
stone. Sometimes dye appears as a residue that rubs off or
white patches. Lapis and Rose Quartz are commonly dyed.
Amethyst and Citrine are often dyed. Black Onyx is permanently
dyed in normal processing.
Jasper is often dipped in petroleum products to bring out color
and to seal it. Emerald is oiled; turquoise is waxed.
Some dealers will try passing off fake stones instead of
natural ones. There are fake stones for most gemstones on the
market. Always ask what stone something is if you are not
certain. Honest dealers will tell you. If a stone looks too
perfect it may be fake, irradiated or dyed. I avoid Laboratory
made products are known as synthetics.