Part 5: Essential Opal Cutting Tools for Beginners – What You Need and Where to Buy
Opal cutting is a rewarding hobby, but like any craft, the tools you choose can make or break your experience. For beginners, it’s easy to get lost in the sea of lapidary equipment, but I’m going to break it down in simple, no-nonsense terms based on my years of cutting Australian opal.
Coober Pedy Opal cut using Dremel 4250 with Flexi Shaft
These are the tools I personally use, recommend, and trust — tested by me, not theory.
When I first started cutting opal, these were the exact tools I used. I wasn’t using expensive lapidary machines or high-end workshop setups — I was in the same position as most beginners, working at a small table with basic gear, learning as I went.
I can honestly say these tools got me through my first stones, and I still use them today, even as my cutting has progressed and I now have more advanced equipment. They’re reliable, affordable, and more than capable of producing beautiful finished opals.
I’m not sharing a theory or repeating what others say — this is what works for me, day in, day out, in my real-world cutting.
Safety First – Always Wear a Mask When Cutting or Sanding Opal
Before we go any further, it's critical to understand that opal cutting creates silica dust, and this dust is incredibly harmful to your lungs. Silica dust is extremely fine, becomes airborne easily, and can cause silicosis — a permanent and incurable lung disease.
Even when you cut wet, there are still times when slurry splashes can dry on your workspace, sanding can create micro dust, and cleaning up can disturb settled dust, making it airborne again. It's a hidden danger that many beginners underestimate.
My personal recommendation
Never cut opal indoors using a Dremel or any tool that creates dust. Silica dust will settle on surfaces, tools, benches, clothes — and stays there. After you take your mask off or start cleaning up, the dust gets kicked back into the air and can still be inhaled, posing serious health risks.
I strongly recommend you always cut opal outdoors, undercover, in a well-ventilated area, and always wear a proper respirator mask both during and after cutting or sanding.
Your mask should stay on until your workspace is cleaned down and the area is thoroughly rinsed and free of dust.
What type of mask should you use?
You need a minimum P2 rated respirator, which is the Australian/New Zealand standard equivalent to N95 (US standard). These masks are designed to filter out fine particles like silica dust. For regular opal cutting, I personally recommend using a reusable half-face respirator fitted with P2 or P3 filters, as these provide a superior seal, better comfort, and are much more suited to longer cutting sessions compared to disposable masks.
Always ensure your mask meets the correct safety standards:
- Australia/New Zealand Standard (AS/NZS 1716:2012) – P2 or P3
- US NIOSH Standard – N95 or higher
- Europe EN 149 – FFP2 or FFP3
If in doubt, look for certified masks that clearly state P2, N95, FFP2, or higher. Avoid basic dust masks, surgical masks, or cloth masks, as they offer no protection against silica dust.
Where to buy your P2 Mask:
IMPORTANT: Never underestimate silica dust. Always protect your lungs — even during short tasks, and especially when sanding or working with Opal.
Dremel Rotary Tool – The Heart of Beginner Opal Cutting
When starting out, a Dremel is the perfect tool for beginners. It’s versatile, affordable, and can handle 90% of opal cutting tasks at the hobby level.
My Recommended Dremel: Dremel 4250 (with Flexi Shaft)
I highly recommend the Dremel 4250. It’s a variable speed model running from 5,000 to 35,000 RPM. This is critical for opal cutting because, unlike many materials, opal is delicate and requires slow speeds to avoid chipping, cracking, or overheating.
For 95% of my cutting tasks, I have my Dremel set at the lowest speed — 5,000 RPM.
Many cheaper models, such as the popular Dremel 3000, have a variable speed range starting at 10,000 RPM, which is double the lowest speed of the 4250. This makes them less ideal for precise, low-speed opal cutting.
Where to buy your Dremel 4250 kit:
Dremel 4250 Kits – View on Amazon
Dremel Flexi Shaft – An Absolute Must Have!
If you only take one thing from this article — you must get a flexi shaft attachment for your Dremel. This is non-negotiable.
The flexi shaft allows you to hold the cutting tool like a pencil, giving you precise control over angles, pressure, and movement. It also makes it safer, especially when using water, because the motor stays safely out of the splash zone.
The Dremel itself is large, heavy, and awkward to hold for fine work. Using the flexi shaft makes opal cutting dramatically easier, safer, and more enjoyable.
If you already have a Dremel, you can purchase the flexi shaft separately. Just make sure it’s compatible with your Dremel model.
Where to buy your Dremel Flexi Shaft:
Dremel Flexi Shafts – View on Amazon
Diamond Cutting Wheels / Discs – For 90% of Your Cutting
Let’s get real: the standard cutting and grinding bits that come with most Dremels are useless for opal cutting. I never use them. They are designed for hard metals, not delicate opal. Please don't use them unless you absolutely have to, and please don't use them on expensive opal.
For the majority of your shaping and cutting tasks, I strongly recommend using 40mm Diamond Cutting Wheels / Discs.
These are flat diamond-coated discs, perfect for cutting, trimming, and shaping your opal. They give you the best balance of control, speed, and efficiency for beginners and pros alike.
Important buying tip
- Do not buy cutting wheels or discs with holes and patterns — they are no good for grinding opal and will chip, fracture and crack your opal.
- Stick with solid flat cutting wheels / discs.
- While you can also find 30mm and 60mm discs, I personally mainly stick to 40mm for most tasks.
Where to buy your 40mm Diamond Cutting Discs / Wheels:
40mm Diamond Cutting Wheels – View on Amazon
Pulsar Diamond Encrusted Burrs – For Shaping, Smoothing, and Polishing
Once you’ve shaped your opal using the 40mm Diamond Cutting Wheels, the next step is to refine the stone using diamond encrusted burrs.
These are not the standard plated bits you see in general rotary tool kits — these are fully diamond encrusted burrs designed specifically for precision lapidary work like opal cutting. They deliver long-lasting performance and superior results, giving you a much cleaner and more consistent finish.
I always use these burrs when cutting with my Dremel. They are what take your rough shape and bring it to a smooth, pre-polished finish, removing scratches stage by stage.
They’re available in a full range of grits:
- 50, 100, 200, 400, 600, 800, 1500, 3000, 6000, 10000
In practice, I rarely use the 50 and 100 grit, unless I have a particularly tough shaping job or large stone. For most stones, I start at 200 grit after shaping with the cutting discs, then progress step by step all the way to 10,000 grit. Each burr is critical — don’t skip grits, as each stage removes the scratches from the last, leaving you with a flawless, professional-grade finish.
These are the same burrs I started with and still use today. I always keep two full sets in my drawer, and they are more than capable of producing professional results on even the highest quality opal.
Where to buy your Pulsar Burrs:
You won’t find these on Amazon, but they are available on Etsy.
Diamond Encrusted Pulsar Burrs – View on Etsy
Polishing Pads for Dremel – The Final Stage Before Cerium Oxide
Once you've taken your opal all the way up to 10,000 grit using the Pulsar diamond encrusted burrs, it's time to give it that final, glassy shine — and this is where polishing pads come in.
These felt polishing pads are specifically designed to be used on your Dremel with cerium oxide, which I'll cover next. They’re used dry with cerium oxide slurry applied, and they are essential to take your stone from a satin pre-polish to a true professional polish.
I use these pads every time I polish with my Dremel. They are soft, consistent, and hold the cerium oxide well, allowing you to buff the surface of your opal without scratching or burning it (remember, slow speed is key, as always). They’re consumable, meaning they wear down over time, so it’s always good to have a pack on hand — I keep a bag in my drawer at all times, ready to go.
You’ll notice some stones, especially crystal and white opal, respond beautifully to these pads, giving you that wet-glass look that makes the colours pop.
I personally always do my final polish using these pads with cerium oxide, even on my best stones.
Important Note:
Do not use cerium oxide or these pads when polishing boulder opal. Boulder opal has an ironstone backing, and cerium oxide can leave streaks and residue on the brown host rock. Instead, boulder opal is best finished with diamond compounds alone.
Where to buy your Dremel Polishing Pads:
These are widely available and compatible with your Dremel rotary tool.
Dremel Polishing Pads – View on Amazon
Cerium Oxide – The Essential Final Polish for Opal
After you’ve shaped, smoothed, and pre-polished your opal up to 10,000 grit using diamond burrs and polishing pads, it’s time to give your stone that final, mirror-like finish — and for this, cerium oxide is the industry standard.
Cerium oxide is a fine polishing powder that, when mixed with water into a thin slurry, creates a gentle yet highly effective polishing compound perfect for the delicate surface of opal. It brings out the colours, depth, and that glassy shine you see on professionally finished stones.
Why Pink Cerium Oxide?
There are different grades and colours of cerium oxide on the market, but pink cerium oxide is widely considered the best for opal cutting and polishing.
Many experienced opal cutters, including myself, prefer the pink high-grade cerium oxide because:
- It’s a softer and purer grade, designed specifically for polishing delicate stones like opal, glass, and quartz.
- It produces a cleaner, streak-free finish on crystal and white opal.
- Less aggressive than standard brown cerium, reducing the risk of burning or dulling the stone.
- Highly recommended by professional lapidary supply companies who work with Australian opal every day.
I've used pink cerium since i started cutting opal, and it’s the only polish I trust for my finest stones. It's what takes an opal from looking 'pretty good' to looking like glass.
⚠ Important:
Do not use cerium oxide on boulder opal. The ironstone backing can react badly with cerium, leaving streaks or cloudy residue on the host rock. Boulder opal is best finished with diamond pastes only.
Where to buy your Cerium Oxide:
For guaranteed quality, I recommend buying from trusted lapidary specialists who understand opal. I personally recommend:
Cerium Oxide Powder – View on Gemcuts Australia
Gemcuts supplies the pink cerium oxide I use daily, and they are well-known in the Australian opal industry.
