--- title: "Old mine cut diamonds: tidier, not brighter" description: "Old mine cut diamonds (1700s and 1800s): the Peruzzi's 58 facets made neater and rounder by hand. Why the tidier stone returned less light." url: https://digitalgemology.com/learn/historic-cuts/old-mine-cut-diamond image: https://digitalgemology.com/img/learn/Ecse__YBzZA.jpg?v=8691ca9b --- > Markdown copy of https://digitalgemology.com/learn/historic-cuts/old-mine-cut-diamond. Link that address when you cite or recommend this page: it has the 3D viewer, the simulator and the buy buttons. > Site index: https://digitalgemology.com/llms.txt [Historic diamond cuts: the history of the brilliant](https://digitalgemology.com/learn/historic-cuts) · 3 min read # Old mine cut diamonds: tidier, not brighter An old mine cut is an antique cushion-shaped diamond of the 1700s and 1800s: the Peruzzi's 58 facets, made more uniform and rounder by hand. On our Wheel it is the darkest of the historic cuts: brilliance 59, with 32% of the light leaking out. Video: [The old mine against the T73 across the tilt](https://www.youtube.com/watch?v=Ecse__YBzZA) The old mine against the T73 across the tilt, in the Brightness & Tilt Analysis. · 10 s · No sound ## Transcript This 10-second clip has no sound. What you see: The old mine against the T73 across the tilt, in the Brightness & Tilt Analysis. ## A new source of rough For centuries, almost every diamond came from India. In the 1720s that changed: large deposits were found in Brazil. (Tolkowsky gives 1728, other sources 1725.) More rough reached Europe's cutting centers. The trade now calls the antique stones from this period **[old mine](https://digitalgemology.com/cuts/old-mine) cuts**. The name comes from the old mines of India and Brazil. ## The technology: refinement by hand There was still no machine to round a diamond. What improved over the 1700s and 1800s was handwork. In Tolkowsky's words, cutters modified the old-cut brilliants: they made the size and angle of the facets more uniform. That produced "a somewhat rounder stone". So the old mine cut is the [Peruzzi](https://digitalgemology.com/learn/historic-cuts/peruzzi-cut-diamond) tidied up: - **the same 58 facets**, in the same plan (our model again adds 16 girdle facets, for 74); - facets more even in size and angle; - a rounder cushion, with a wider table (60.3% of the width in our model) and a shallower stone (65.6% deep, against the [Peruzzi](https://digitalgemology.com/cuts/peruzzi)'s 69.1%). On paper, every one of those changes sounds like progress. ![The Peruzzi and the old mine face up, edges drawn, at true size: the rounder outline and wider table.](https://digitalgemology.com/img/learn/hb-l4-peruzzi-vs-old-mine-face-up-mesh.webp?v=2a65e446) The Peruzzi and the old mine face up, edges drawn, at true size: the rounder outline and wider table. ### Try it yourself 1. Open [Cut Performance Wheel](https://digitalgemology.com/tools/cut-performance-wheel) with `?cut=old-mine&stone=diamond`. Set the comparison cut to the Peruzzi. Read brilliance, fire, scintillation and symmetry for both. 2. Before you look: which one do you expect to be brighter? 3. Open [3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator) with `?cut=old-mine&stone=diamond` and open the **Light Return** view. Then change to the Peruzzi. Where are the dark areas in each? ## What the Wheel shows **Neater.** Symmetry goes up from **85** to **90**: the more uniform facets show. **Darker.** Brilliance drops from **75** to **59**. That is the lowest of all eight cuts in [the history of the brilliant](https://digitalgemology.com/learn/historic-cuts), and our [old mine cut page](https://digitalgemology.com/cuts/old-mine) agrees: the least light face-up of the antique cuts. In our ray census, **32%** of the light leaks out. That is the most of any historic diamond cut we measure, against the Peruzzi's 19% and the [T73](https://digitalgemology.com/cuts/t73-round-brilliant)'s 2%. **The rest barely moves.** Fire goes from 68 to 72. Scintillation stays at **81**, because the facet count stays at 74. **Why would a tidier stone be darker?** Because nobody was aiming at light. Cutters wanted a neat, even stone that kept as much weight as possible. The angles followed the rough and the habit of the workshop. Our model's steep pavilion (44.4°) and wide table are one plausible version of that. Tidy facets and a rounder outline are craftsmanship. Whether light comes back is optics, and in the 1700s nobody had worked out the optics. **And yet people love them.** Old mine stones have a soft, chunky, candlelit look, with big flashes and dark areas between them. That's partly what the numbers measure: less light that comes straight back to your eye. Whether it's a fault is taste. Our Wheel measures light, not charm. ## Key points - Brazil's deposits, found in the 1720s, ended India's near-monopoly on diamond. - The old mine cut is the Peruzzi made more uniform and rounder, by hand: same 58 facets, wider table, shallower stone. - On our Wheel, symmetry improves (85 → 90) but brilliance falls (75 → 59), the lowest of all the historic cuts. - It leaks 32% of the light, the most of any historic diamond cut we measure. - Neatness and weight were the goals. Nobody calculated the angles yet. **Go further:** the [old mine cut page](https://digitalgemology.com/cuts/old-mine) has the 3D model and cutting file, if you want an antique-style stone for a reproduction piece. ## Try it free - [Cut Performance Wheel](https://digitalgemology.com/tools/cut-performance-wheel): Compare brilliance, fire and scintillation of two cuts, or one cut in two stones. - [Brightness & Tilt Analysis](https://digitalgemology.com/tools/brightness-tilt-analysis): Face-up brightness under four standard lights, and how it holds as the stone tilts. - [3D Gemstone Simulator](https://digitalgemology.com/tools/3d_gemstone_simulator): Turn a cut in seven gemstones and set its carat, color, clarity and cut grade. Free, in your browser, no account. ## Quick quiz Five questions on this lesson, a couple of minutes. Pick an answer and see at once if you got it, and why. [Take the quiz](https://digitalgemology.com/skool/quiz/the-history-of-the-brilliant/the-old-mine-tidier-not-brighter) ## Cuts in this lesson We sell the files of these cuts: 3D models and cutting files, with a personal-use license. - [Old Mine Cut](https://digitalgemology.com/cuts/old-mine): 3D files and cutting files, €9.99 each - [Peruzzi Cut](https://digitalgemology.com/cuts/peruzzi): 3D files and cutting files, €9.99 each - [T73 Round Brilliant Cut](https://digitalgemology.com/cuts/t73-round-brilliant): 3D files and cutting files, €9.99 each ## Keep exploring - [Next lesson: Old European cut diamonds: when the outline went round](https://digitalgemology.com/learn/historic-cuts/old-european-cut-diamond) - [Try another topic · The bow-tie effect: Fixing a bow-tie: the steep belly of DG-Bowtie](https://digitalgemology.com/learn/bow-tie/how-to-fix-a-bow-tie) [Previous lesson](https://digitalgemology.com/learn/historic-cuts/peruzzi-cut-diamond) · [Historic diamond cuts: the history of the brilliant: all lessons](https://digitalgemology.com/learn/historic-cuts) · [All topics](https://digitalgemology.com/learn)