Chrome Tourmaline is one of the top commercial gemstones available in the market today. Like all Tourmaline, Chrome Tourmaline sets and wears well in almost any jewelry.
Keep in mind that these are my personal opinions and experiences, other people may have different ones.
Color – Chrome Tourmaline is an intense emerald green color which is caused by the “chrome” in the gemstone. There are more involved definitions but basically the chrome is what causes the color and chrome must be present in the gem stone for it to be called chrome Tourmaline.
What I look for… Look for pure medium Emerald green, some people prefer Chrome Tourmaline a little on the dark side because of the deep intense green flash. I personally prefer it with medium saturation and intense Emerald green color. I generally want pure green (this color of course is more rare and difficult to find), in many stones you will see either a blue/black tone or a yellow tone. A stone with either of these color tones I would grade at a lower level.
Saturation – Chrome Tourmaline tends to be very intense in color and saturation. What this means is that the vast majority of Chrome Tourmaline is too dark if it is not cut properly or in the correct size (usually cut too large for the saturation of the rough). Be very careful to buy a stone that has good quality color and fire in normal light conditions. Gem show or dealer lighting is very intense and a stone will usually look much brighter than it really is in normal light conditions.
Clarity – High clarity IF to VVS stones are rare, but available. Of course the lower clarity material is more readily available in the commercial market, but better quality and clarity can be found. High clarity IF to VVS stones are available in the high end commercial market and the American quality cut market (look at my cut stones you will see them).
Treatments – Generally there are no treatments of any kind.
How does a buyer protect themselves from undisclosed treatments? The first line of defense is deal with a quality, experienced gem dealer with a good reputation. Dealing with some one that is an honest and experienced gem dealer is the best way to go.
Tips for Spotting Treatments – No treatments. But some times people are selling Verdelite (green) Tourmaline as chrome. It is easy to test for the chrome content using a Chatham Filter. The stones with chrome in them will show as reddish in the filter. The stones that have no chrome and are not reddish in the filter are not Chrome Tourmaline.
Durability – Tourmaline of all types has good durability and can be set in about any type of jewelry. The only exceptions are stones of low clarity (read that as having flaws) that maybe weakened because of their flawed structure.
Sizes – Chrome Tourmalines are available in mostly smaller size ranges, depending on your budget. 1 carat to 2 carat stones are not difficult to find. 3 carat to 8 carat stones are around and can be found, although not plentiful. Over 8 carats is not common, particularly light enough in color to look good cut.
Cuts & Styles – Chrome Tourmalines are available in about any cutting and style. I find as the stones become more saturated in color (larger) that brilliant cuts and checker boards work best. If the stone is not too dark about any type of cut you like can be done.
Cutting Quality – Is the stone cut to high custom standards? Or is the stone cutting the normal commercial quality? Cutting is very important and significantly effects the value of the finished gem stone. If the stone is a high quality cut and particularly cut by a well known cutter it will increase the stones quality and value, many times as much as double or more.
Note: There are also different levels of commercial cutting. Some commercial cutting while not any where near the standard of top quality (like mine), is significantly better than low quality commercial cutting. A sign of good quality commercial cutting is that the stone is symmetrical and the proportions (table, crown, pavilion) are correct and the stone has a good polish and reflection.
Commercial Market (trade) – Chrome Tourmaline is one of the major players in the top commercial colored stone market. The vast majority of the Chrome Tourmaline you will see is too saturated (dark) and poorly cut in my opinion. Be sure and look around for a real quality stone. Yes, it will cost more…
Origin – Chrome Tourmaline is really only mined in Tanzania Africa at one regional location.
Value – High quality Chrome Tourmalines are increasing in value and I think will continue to do so. There is never any way to be certain but the way the gem stone market is trending just about any quality stone will appreciate.
Collectability – Collectors discovered Chrome Tourmaline early on and quality stones, particularly of decent size are sought after and bring more money than almost any other color.
Questions to ask when buying
Is the stone natural or man-made? – There is no man-made Tourmaline, but I have seen some substitutes in the market from time to time. This is always a good question to ask.
What is the clarity of the stone? – I would only recommend stones that are IF to VS in Indicolite Tourmaline. Be aware of the different and some times miss leading grading systems some labs and sellers use.
Is the stone heated? – Heat is some times used to lighten the color of Tourmaline or some times eliminate an unwanted secondary color or tone. I have no issue with heating as stone as long as the information is disclosed. Some purists want only a natural “unaltered” stone. This is a personal decision.
Is the stone heated and Irradiated? – Like I said, a lot of the commercial stones available are heated and some are irradiated. I do not mind the heat, but when you are irradiating a stone you are putting color in that was never there in the first place. I generally do not sell or recommend irradiated stones.
Note: Heat only modifies the color of a stone, lightens or heats out an undesirable color. It does not put some thing into the stone that did not already exist. Heat is some thing that happens in mother nature, so I personally do not find it that much of a problem.