There are basically six distinct types of natural opal including black opal, crystal opal, white opal, fire opal, matrix opals, and boulder opal. The first four in this list are all solid opal while matrix opal and boulder opal have the host rock included. Boulder opals consist of a layer of opal that has formed in crevices of the host rock ironstone. When the stone is cut the host rock is left on the backside of the cabochon. This provides a dark background to the thin layer of solid opal. This is also left on for strength, as the thin layer of opal would be too weak on its own. Matrix opal is ironstone or clay stone in which the opal material has formed into the pores of the host rock. This type of opal is treated with a sugar solution and then acid to carbonize the sugar and create a dark background. Without this treatment the host rock appears brown and masks most of the play of color.
Black opal is solid opal that has a dark or black background tone, white opal has a light or white background tone, and crystal opal has a transparent background tone. Fire opal has an orange or red body tone and comes primarily from Mexico. Australia produces most of the high quality opal although various types can be found worldwide. Black opal is the most highly sought after type of opal followed by boulder opal, crystal opal, and fire opal. Matrix opal and White opal are the cheapest types of opal but still can reach hundreds of dollars per carat in their finest forms. Pictures of opals can be seen at
I find photographing loose gemstones buy online to be an art form I may never fully conquer but I wanted to share a few tips I’ve learned over the years. My goal is not really to create an artistic photo of the gem but rather to depict the gemstone in the most accurate way. Lighting is by far more important than your camera setup but a few features on your camera are essential. A camera with manual mode that allows you to choose a custom white balance in Kelvin is a must as well as a good macro lens. I prefer using a focal length of 105mm macro lens so that I’m far enough from the gemstone to use my lighting setup. With this lens you can get about 6-8 inches away from the gem allowing for some flexibility.
I use two different lighting setups depending on what type of stone I’m shooting. I like to use the LED ring light from Table Top Studio for some gems and usually white balance around 6700K give or take. Even with proper white balancing though the LED lights will overemphasize the blue in gemstones. The LED setup works pretty well for green emeralds though. I also use a light tent with a couple daylight fluorescent bulbs that I white balance at around 5600K. For faceted gemstones I use a light on each side of the tent but if I’m shooting cabochons I use only one.
One mistake is to try to shoot gemstones pictures at your highest aperture setting. Often a really high depth of field will bring out too many details from the back of the gem and make it look much worse than with your naked eye. Try experimenting with a lower f-stop like f-11 or f-8 and see how it looks.