Conoscope Interference Sphere Ball for Polariscope. Wide 15mm Lens. Gemstones

Overall I like it, and it does what it’s supposed to do. The only minor issue is the handle feels a bit small when trying to position it precisely. Not a big deal, just something I noticed during longer use sessions.

The tool itself works fine, but don’t expect instant results. It took me several tries before I could clearly see the interference patterns. Like many gem tools, there’s a learning curve. Once you get used to it though, it becomes very useful.

I don’t have a full professional lab—just a small setup at home—and this fits perfectly into that. It’s affordable and gives you more insight without needing expensive equipment. Great for hobbyists like me.

Before I got this, my polariscope felt a bit limited. I could see light/dark reactions, but not much beyond that. This tool opens up a whole new level of detail. It’s honestly what made the polariscope feel like a complete system.

The wider 15mm lens gives a comfortable viewing area. I’ve tried smaller ones before, and this feels easier on the eyes. The interference patterns are easier to spot without constantly repositioning.

I like how simple it is. There’s no setup—just hold it over the stone while using the polariscope. It’s lightweight and easy to control, which makes a big difference when you’re trying to line things up just right.

This tool really shines when you’re trying to determine whether a stone is uniaxial or biaxial. That’s something I struggled with before, but using this makes it much easier to interpret the results

The glass sphere is clear and distortion-free from what I can tell, and the handle makes it easy to position. I wasn’t expecting much at this price point, but it feels like a proper tool rather than a cheap accessory. Fits nicely with my setup.

I’m still learning gemology, and this has been incredibly helpful. At first, I wasn’t sure what I was seeing, but after some practice, I started recognizing patterns. It’s definitely something that takes a little patience, but once you get it, it’s very rewarding.

If you already have a polariscope, this is basically a must-have. It helps magnify and visualize the optical axis much more clearly . I’ve been practicing with quartz and a few other stones, and the patterns are much easier to interpret now.

This feels like one of those accessories you don’t realize you need until you try it. I was already using a polariscope, but this adds another layer of detail. The 15mm lens gives a nice clear view, and the glass ball seems well made. It’s now part of my regular workflow when checking stones.

I had a polariscope for a while but didn’t fully understand what people meant by “interference figures” until I added this conoscope. The moment I used it, everything clicked. Being able to actually see the optic axis patterns made a huge difference in how I interpret stones. It’s a small tool, but it completely changes what you can get out of a polariscope.

The average quality is good, it's a very good replacement, just the handle it's a little bit short, you must have small finger

I have been so happy with the Gem tools, like this conoscope, that I have received from this site! I have officially bookmarked this and it is my go to whenever I need a new tool. The quality is amazing and the prices are very affordable. This is a really useful tool, and it is a convenient size. Free shipping is always nice, especially when it is fast! I couldn't be happier with this.