GemSim

Design your gemstone before you cut it. GemSim is a free 3D gemstone faceting simulator for designing, visualizing, and refining gemstone cuts before touching a real stone. Whether you’re learning faceting, experimenting with new ideas, or recreating published designs, GemSim gives you powerful design tools on iPhone, iPad, and the web. Interactive 3D Simulation • Rotate, zoom, and inspect your gemstone from any angle • See design changes instantly in 3D • Preview gemstones with realistic rendering • Analyze light return, windowing, and head shadow Faceting Design Editor Create and modify designs with detailed faceting controls. • Add, edit, reorder, duplicate, and delete tiers • Control facet angles, depths, and indices • Create and reuse custom index sequences • Select meet points directly from the 3D model • Use fractional indexes for advanced designs • Toggle tier visibility and undo changes Frost Edge Create decorative frosted edges directly from the 3D model. • Select individual edges or groups of symmetrical edges • Control the width of the frost strip • Frost crown, pavilion, and girdle edges • Automatically generate editable frost tiers • Preview frosted facets with realistic rendering • Include frosted facets in printable cutting diagrams Design Library Explore thousands of classic and public gemstone designs. Search by shape, design name, designer, dimensions, and more. Load a design and immediately start exploring or editing it. Cloud Storage & Sharing Create a free GemSim account to save designs in the cloud and access them across devices. • Store up to 100 cloud designs • Share designs using public links • Share privately with specific GemSim users • Choose View Only or View + Copy access • Manage access independently for each design An account is optional. Core design and simulation features remain available without signing in, and you can continue saving and opening files locally. Import, Export & Print • Save editable GemSim project files • Export designs as 3D models • Generate printable cutting diagrams and instructions • Use local files without an account Learn and Experiment GemSim is built for beginning cutters, experienced faceters, hobbyists, students, and gemstone designers. Experiment with angles, indices, proportions, meet points, frost patterns, and complete designs without risking valuable rough material. Make mistakes on the screen instead of on the dop. GemSim is free to use, with no subscription required to create, edit, and simulate gemstone designs. Start designing today and discover what’s possible before you make the first cut.