Diamond Selector II testers - genuine or fake?



In the chart below, the more features you can see that are listed on the right, the more likely it is to be a copy.

Original CULTI Diamond Selector II, made in Japan  Copies of Diamond Selector II, made in China

The instructions are on glossy paper in reasonably good English, and the guarantee slip is in English too.

Some of the copies have the same paperwork as the original, but many instructions are written in poor English; sometimes the guarantee slip is in English and Chinese (definitely a copy!)

If it has no instructions at all, be suspicious. If the instructions don't seem to tally with what the tester, be suspicious. If there's no guarantee slip, be suspicious.

In addition to DIAMOND SELECTOR II, the box has the CULTI logo on four sides, and Made in Japan culti on two sides.

 The box is just marked DIAMOND SELECTOR II, and nothing else.

 The pouch is embossed CULTI on the flap.

The pouch is unmarked.

 The pouch is made of a good quality vinyl and has an open compartment (containing the stone-holder) on the outside at the bottom.

The pouches vary a lot on the copies, some are thin vinyl, on some the stone-holder compartment is fastened with Velcro flap.

 The chart on the back of the tester is marked in degrees Celsius.

 The chart on the back of the tester is marked in degrees Fahrenheit.  

 Under the chart on the back of the tester is Made in Japan culti.


The sensitivity knob (marked, "volume") works smoothly.

 The sensitivity knob (marked, "volume") might work smoothly, but might be stiff or loose.

The battery wire is three inches long, easy to replace battery.

 The battery wire is only two inches long, fiddly to replace battery, the wire is easily broken, this is not covered by the guarantee.

The segments of the LEDs go like this: 4 green then 4 yellow then 4 red.

There might be variations from manufacturer to manufacturer but, typically, 4 red then 5 orangey-yellow then 3 blue.



DIAMOND SELECTOR II (Chinese copy), OUR REF. DT-DS. Chinese copy, good quality. I know this particular factory well, they are not the cheapest but they only use good quality components and are reasonably good with their quality control. These testers only work at room temperature (between 18 degrees C. and 27 degrees C).  Within this temperature range these do give a correct reading most of the time (correct maybe 80% to 85% of time, I guess).  

DIAMOND SELECTOR II (original Japanese CULTI),  OUR REF. DT-CULTI. Although these are more expensive than the copies, we are selling them for a fraction of the original retail price, this is good value for a 'cheapie' that works well.  As with the others, they must be used between 18 degrees and 27 degrees C. to give correct results.  My best estimate: they give correct results 95% of the time.

QUICKTEST DT5 (Quicktest's own brand), OUR REF. DT5. This is not a DIAMOND SELECTOR at all, but the casing is similar. The chart on the back shows diagrams of diamonds actual-size, rather than a chart of numbers; very clear instructions; designed by QUICKTEST so that it also works in the cold, so it can be used for buying at outside venues in the winter - unlike the DIAMOND SELECTORS which must be used at room temperature, otherwise they give false readings.  These have the QUICKTEST logo on the front of the tester and DT5 on the back. My best estimate: they give correct readings 99% of the time.

DIAMOND SELECTOR II (Chinese copy available to special order)

The most ‘basic’ quality, just like you see on eBay and Amazon.  I did once sell these, but most were returned within a few months because the readings were inconsistent or they simply fell apart. Then a UK wholesaler asked us to get them 100, which we did.  If you are a wholesaler, send us your details and we can give you a quote, minimum order 100, trade only. These look identical to the other Chinese copies but their components are the cheapest possible, and to keep the price down the quality control is poor too - some of them work fine for a year, some break down in a few weeks...or days. I offer no guarantee whatsoever.