Question I’ve come across what I believe is an unusual specimen and I’m looking for someone to help me come up with an approximate value for this. I’ve got a brilliant cut sphalerite that is 11.5 ct and 13mm across. It’s a brilliant…

Question In my quest for a refractometer, someone suggested that I purchase a reflectometer as a more affordable alternative. However, I’m having difficulty getting much information on this tool as it relates to gemstones. Do you know anything…

Question I was a bit disappointed with your description of opal wearability as “Poor.” Bit harsh I think. If it’s worn as a ring I could understand the comment, but how about brooches and pendants? Not too much abrasive action on stones in…

Question I recently bought a rhodolite. It’s clean and has a beautiful dark red color. My problem is simply that I’m wondering if it’s truly rhodolite or some other type of garnet. This is the first time I’ve purchased this garnet…

Question From different sources, I’ve heard that chrysoprase fades in sunlight or heat. How sensitive is it? Does normal daytime wear affect the stone color? Should chrysoprase be worn mostly at night to preserve its vivid color? Can the color…

Question Could you explain the difference between topaz and citrine gemstones? I recently had appraised what I believed to be a 1-carat topaz. When I bought the gem 18 years ago, the jeweler appraised it as a topaz. Now, the new appraisal says…

Question What’s the best way of wearing gemstones most suited to me in terms of health? I want to create a wedding ring for myself with a setting in which the stones are actually touching my skin. Is there any wisdom on this you can share with…

Question I’m getting started in gemology but I think I have a bad problem. I’m red, green, and brown colorblind. I see and enjoy colors but I don’t know what colors I’m looking at. I love faceting stones and have recently completed a new…

Question Do you think emeralds and peridots can be combined in jewelry? I’m interested in designing a unique engagement ring.  I want it to feature my and my fiancé’s birthstones as accents to a diamond center stone. Mine is emerald.  His…

Question I want to know more about golden beryl. Is it rare? What is its wholesale and resale value? Is it a good stone for jewelry? Answer Golden beryl is also called heliodor, which is Greek for “gift of the sun.” This gem’s value depends…

Question What are the chances that the stone in my 40+ year-old ring is a real alexandrite? It changes color from blue to a deep purple. The gem is emerald cut and it’s in a very pretty setting. The ring was a gift for my June…

Question I happened upon some opal in the raw when I was traveling in Honduras. There were ten pieces in a bottle filled with water. The man who sold them to me said I needed to keep them underwater. I’d like to have the opals shaped and polished…

Question I’m fascinated by agate, especially the kind found in basaltic or other lava cavities.  The stones from Botswana and Brazil are my favorites.  These were formed at some time in the remote past. After the lava had hardened, water…

Question Recently someone offered me a chameleon diamond that changed shades from yellow/green to yellow. She tried to convince me that it was different than a color change gemstone. I didn’t know enough to argue. Can anyone expand on…

Question Aquamarine and most other members of the beryl family have nice big, clean crystals. Why are emeralds different in general? What causes emerald fractures? No one has given me a good answer yet. Isn’t a beryl a…

Question I have some questions about polishing silver jewelry. I’ve tried a number of methods that work well, but none are particularly easy. I’d love to hear some suggestions for making polishing silver easier. I was also wondering if anyone has…

Question A friend of mine showed me some gems he claimed were white aquamarines. I told him those were not aquamarines, but he insists they are. Supposedly he got a good deal on them because they are colorless instead of blue. Is there actually…

Question My granddad was a gemologist. When he passed away 10 years ago, I inherited many of his things, including lots of gemological instruments. One of these is a mystery to me. It’s a small instrument about 5 cm in length. It has a sticker…

Question I want to get an emerald pendant for a Christmas present. I’ve talked to some jewelers who are trying to push lab-created emerald pieces. I’ve been told synthetic emeralds are just like the genuine stones. They also say synthetics are…

Question I’m confused about the effect of faceting on a gem’s value. Specifically, what’s the difference in value between factory-cut and custom-cut gemstones? Is that something you can calculate? I was recently told that the majority of my gems…

Question I’m a novice gemology student. I’m traveling to Turkey in the near future and I’d love to know more about Turkey’s gemstones. What might I find on my visit? I’ve got my gem identification book ready to go. Any information would be…

Question I’d love to have some feedback on the identity of the gemstones of the breastplate of Aaron. In Exodus 28:15-21, the breastplate of Aaron is described in great detail. In the Tanakh, the Hebrew Bible, a different gemstone is listed for…

Question I’m a little confused about chert and flint. In your gemstone listing entry on quartz, you identify both chert and flint as examples of cryptocrystalline quartz. They are described together as “opaque, dull gray, or whitish chalcedony,…

Question I’ve never been to the Tucson Gem and Mineral Show but I’ve heard many stories. I’m wondering, just how good is it really? Would any International Gem Society (IGS) members be willing to share their reviews of this event? What did you…

Question A friend of mine was going through some old stuff in his attic and found something labelled “atomic glass.” Since it looked like a yellow gem, he gave it to me. (By the way, it’s preformed to a nice, big emerald cut). Any ideas what…

Question I love working with opal from Spencer, Idaho. On rare occasions, I turn up a star stone. I know star opals are very rare. So as you can imagine, I’m having a heck of a time trying to put a realistic value on what I cut. Does anyone have…

Question Has anyone ever heard of Serengeti rubies? We bought two. The seller told us they were new to the US. Each is about 1 carat and a 7×5.3 mm oval. These stones are very clean and pink/purple in color. How rare are Serengeti rubies and…

Question I’m an engineering geologist mainly involved in tunnel construction. I also collect gemstones. My special interest is in color-change minerals. I’ve been involved in studies of a special color-change phenomenon, the Usambara effect. I’m…

Question Help me! I’ve been offered some rubies at a fabulous price but I’m scared to buy them. Why? There is a lot of money involved. (At least it’s a lot for me). This dealer has a package of large rubies, mostly 1 to 3 carats. They have lots…

Question I was told years ago that natural rubies fluoresce but lab-grown rubies will not. Recently someone told me the opposite. He says that synthetic rubies fluoresce but natural stones won’t. Can you settle this? Ken Answer All rubies…

Question I came across this statement and was wondering if anyone can verify it: “A diamond is the hardest natural substance on earth, but if it is placed in an oven and the temperature is raised to about 763º Celsius (1405º Fahrenheit), it…

Question I’m having some emerald gemstones appraised by a Master Gemologist. Since I’m looking at selling the items I’m dealing in wholesale, do you know where I can find a list of gemstone wholesale prices? I want to familiarize myself with the…