Our Gemstone Cutting Experts

Stefan Austermühle

Stefan Austermühle is not only the CEO of Gemrock, but also our Master Gemcutter, Gemstone Cutting Expert, and Product designer. Stefan laid the groundwork for his lapidary art by getting trained by old-school US-based master cabochon cutters. He always attends our Lapidary Cutting-Service Clients personally and supports their product development with expert advice based on his extensive cutting experience with many Peruvian and other materials from around the world. He often still takes the time to cut the unusual shapes or rare materials himself. He is also responsible for training and knowledge transfer to our in-house gemcutters and for production oversight and quality control.

Stefans Gemstone Cutting Expertise

81 types of stone and counting

A complete list of all the stones Stefan has been cutting.

Agate (Peruvian Sunset Agate)

Based on his long experience sourcing and cutting Agate, Stefan also developed a unique Agate gemstone Quality Standard, which helps you to distinguish jewelry-grade Agate material from low-quality material and avoid wasting your money on bad quality.

Agate (Alaska)

Agate (Graveyard Point Plume Agate)

Agate (Lace Agate)

Agate (Laguna Agate)

Agate (Medicine Bow Agate)

Agate (Moss Agate)

Agate (Polka Dot Agate)

Angelite

Based on his long experience sourcing and cutting Angelite, Stefan also developed a unique Angelite gemstone Quality Standard, which helps you to distinguish jewelry-grade Angelite material from low-quality material and avoid wasting your money on bad quality. 

Apatite (Peru)

Based on his long experience sourcing and cutting Apatite, Stefan also developed a unique Apatite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Apatite material from low-quality material and avoid wasting your money on bad quality.

Banded Aragonite (Peru)

Based on his long experience sourcing and cutting Aragonite, Stefan also developed a unique Aragonite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Aragonite material from low-quality material and avoid wasting your money on bad quality.

Coati Aragonite (Peru)

Based on his long experience sourcing and cutting Coati Aragonite, Stefan also developed a unique Coati Aragonite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Coati Aragonite material from low-quality material and avoid wasting your money on bad quality.

Red Aragonite (Peru)

Based on his long experience sourcing and cutting Red Aragonite, Stefan also developed a unique Red Aragonite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Red Aragonite material from low-quality material and avoid wasting your money on bad quality.

Tiger Aragonite (Peru)

Based on his long experience sourcing and cutting Tiger Aragonite, Stefan also developed a unique Tiger Aragonite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Tiger Aragonite material from low-quality material and avoid wasting your money on bad quality.

Atacamite (Peru)

Based on his long experience sourcing and cutting Atacamite, Stefan also developed a unique Atacamite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Atacamite material from low-quality material and avoid wasting your money on bad quality.

Azurite “Ocean Blue” (Peru)

Based on his long experience sourcing and cutting Azurite, Stefan also developed a unique Azurite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Azurite material from low-quality material and avoid wasting your money on bad quality.

Black Jade / Lemurian Jade (Peru)

Based on his long experience sourcing and cutting Azurite, Stefan also developed a unique Azurite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Azurite material from low-quality material and avoid wasting your money on bad quality.

Caramel Calcite (Peru)

Based on his long experience sourcing and cutting Caramel Calcite, Stefan also developed a unique Caramel Calcite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Caramel Calcite material from low-quality material and avoid wasting your money on bad quality.

Cherry Blossom Stone (also falsly sold as Cinabrite (Peru)

Based on his long experience sourcing and cutting Cherry Blossom Stone, Stefan also developed a unique Cherry Blossom Stone Gemstone Quality Standard, which helps you to distinguish jewelry-grade Cherry Blossom Stone material from low-quality material and avoid wasting your money on bad quality.

Chocolate Calcite (Peru)

Based on his long experience sourcing and cutting Chocolate Calcite, Stefan also developed a unique Chocolate Calcite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Chocolate Calcite material from low-quality material and avoid wasting your money on bad quality.

Chrysocolla: Pure (Peru)

Based on his long experience sourcing and cutting Chrysocolla, Stefan also developed a unique Chrysocolla Gemstone Quality Standard, which helps you to distinguish jewelry-grade Chrysocolla material from low-quality material and avoid wasting your money on bad quality.

Chrysocolla: Classic mix (Peru)

Based on his long experience sourcing and cutting Chrysocolla, Stefan also developed a unique Chrysocolla Gemstone Quality Standard, which helps you to distinguish jewelry-grade Chrysocolla material from low-quality material and avoid wasting your money on bad quality.

Chrysocolla: Puree (Peru)

Based on his long experience sourcing and cutting Chrysocolla, Stefan also developed a unique Chrysocolla Gemstone Quality Standard, which helps you to distinguish jewelry-grade Chrysocolla material from low-quality material and avoid wasting your money on bad quality.

Chrysocolla: Tourquoise-colored (Peru)

Based on his long experience sourcing and cutting Chrysocolla, Stefan also developed a unique Chrysocolla Gemstone Quality Standard, which helps you to distinguish jewelry-grade Chrysocolla material from low-quality material and avoid wasting your money on bad quality.

Chrysocolla: “Water & Wine” (Peru)

Based on his long experience sourcing and cutting Chrysocolla, Stefan also developed a unique Chrysocolla Gemstone Quality Standard, which helps you to distinguish jewelry-grade Chrysocolla material from low-quality material and avoid wasting your money on bad quality.

Chrysocolla: “Il Fresco” (Peru)

Based on his long experience sourcing and cutting Chrysocolla, Stefan also developed a unique Chrysocolla Gemstone Quality Standard, which helps you to distinguish jewelry-grade Chrysocolla material from low-quality material and avoid wasting your money on bad quality.

Copper in Quartz

Copper Ore

Copper Ore (Pensylvania, USA)

Epidote Crystal (Peru)

Based on his long experience sourcing and cutting Epidote Crystals, Stefan also developed a unique Epidote Gemstone Quality Standard, which helps you to distinguish jewelry-grade Epidote material from low-quality material and avoid wasting your money on bad quality.

Epidote Fan-shaped Crystal (Peru)

Based on his long experience sourcing and cutting Epidote Crystals, Stefan also developed a unique Epidote Gemstone Quality Standard, which helps you to distinguish jewelry-grade Epidote material from low-quality material and avoid wasting your money on bad quality.

Indigo Gabbro

Green (Nephrite) Jade (Peru)

Based on his long experience sourcing and cutting Green Jade (also called Nephrite Jade or Greenstone), Stefan also developed a unique Green Jade Gemstone Quality Standard, which helps you to distinguish jewelry-grade Green Jade material from low-quality material and avoid wasting your money on bad quality.

Granite: Morning Rose Granite (Peru)

Based on his long experience sourcing and cutting Morning Rose Granite, Stefan also developed a unique Morning Rose Granite Quality Standard, which helps you to distinguish jewelry-grade Morning Rose Granite material from low-quality material and avoid wasting your money on bad quality.

Granite, K2

Hematite with Mica (Peru)

Based on his long experience sourcing and cutting Hematite, Stefan also developed a unique Hematite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Hematite material from low-quality material and avoid wasting your money on bad quality.

Huanucite (Peru)

Based on his long experience sourcing and cutting Huanucite, Stefan also developed a unique Huanucite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Huanucite material from low-quality material and avoid wasting your money on bad quality.

Jasper: Peruvian Jasper (Peru)

Based on his long experience sourcing and cutting Jasper, Stefan also developed a unique Jasper Gemstone Quality Standard, which helps you to distinguish jewelry-grade Jasper material from low-quality material and avoid wasting your money on bad quality.

Jasper: Landscape Jasper (Peru)

Based on his long experience sourcing and cutting Jasper, Stefan also developed a unique Jasper Gemstone Quality Standard, which helps you to distinguish jewelry-grade Jasper material from low-quality material and avoid wasting your money on bad quality.

Jasper: Landscape Jasper (USA)

Jasper: Owyhee Jasper (USA)

Jasper: Leopard Skin Jasper

Lapis Lazuli (Afghanistan)

Leopardite (Peru)

Based on his long experience sourcing and cutting Leopardite, Stefan also developed a unique Leopardite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Leopardite material from low-quality material and avoid wasting your money on bad quality.

Lizardite (Norway)

Malachite (Peru)

Manganocalcite (Peru)

Based on his long experience sourcing and cutting Manganocalcite, Stefan also developed a unique Manganocalcite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Manganocalcite material from low-quality material and avoid wasting your money on bad quality.

Milky Quartz (Peru)

Based on his long experience sourcing and cutting Quartz, Stefan also developed a unique Quartz Gemstone Quality Standard, which helps you to distinguish jewelry-grade Quartz material from low-quality material and avoid wasting your money on bad quality.

Obsidian: Mahogany Obsidian

Obsidian: Spider Web Obsidian

Opal: Black Iris Opal (Peru)

Based on his long experience sourcing and cutting Black Iris Opal, Stefan also developed a unique Black Iris Opal Gemstone Quality Standard, which helps you to distinguish jewelry-grade  Black Iris Opal material from low-quality material and avoid wasting your money on bad quality.

Opal: Blue Andean Opal (Peru)

Based on his long experience sourcing and cutting Blue Andean Opal, Stefan also developed a unique Blue Andean Opal Gemstone Quality Standard, which helps you to distinguish jewelry-grade Blue Andean Opal material from low-quality material and avoid wasting your money on bad quality.

Opal: Dendritic Opal

Opal: Dendritic Pink Opal (Peru)

Based on his long experience sourcing and cutting Pink Opal, Stefan also developed a unique Pink Opal Gemstone Quality Standard, which helps you to distinguish jewelry-grade  Pink Opal material from low-quality material and avoid wasting your money on bad quality.

Opal: Boulder Pink Opal (Peru)

Based on his long experience sourcing and cutting Pink Opal, Stefan also developed a unique Pink Opal Gemstone Quality Standard, which helps you to distinguish jewelry-grade  Pink Opal material from low-quality material and avoid wasting your money on bad quality.

Opal: Angel Skin Pink Opal (Peru)

Based on his long experience sourcing and cutting Pink Opal, Stefan also developed a unique Pink Opal Gemstone Quality Standard, which helps you to distinguish jewelry-grade  Pink Opal material from low-quality material and avoid wasting your money on bad quality.

Pinolite (Austria)

Pinolite (Canada)

Based on his long experience sourcing and cutting Black Iris Opal, Stefan also developed a unique Black Iris Opal Gemstone Quality Standard, which helps you to distinguish jewelry-grade  Black Iris Opal material from low-quality material and avoid wasting your money on bad quality.

Pyrite: Chispa (Peru)

Based on his long experience sourcing and cutting Pyrite, Stefan also developed a unique Pyrite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Pyrite material from low-quality material and avoid wasting your money on bad quality.

Pyrite: Crystal Cluster (Peru)

Based on his long experience sourcing and cutting Pyrite, Stefan also developed a unique Pyrite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Pyrite material from low-quality material and avoid wasting your money on bad quality.

Pyrite: Cocada (Peru)

Based on his long experience sourcing and cutting Pyrite, Stefan also developed a unique Pyrite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Pyrite material from low-quality material and avoid wasting your money on bad quality.

Pyrite: Solid, also called “Marcasite” (Peru)

Based on his long experience sourcing and cutting Pyrite, Stefan also developed a unique Pyrite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Pyrite material from low-quality material and avoid wasting your money on bad quality.

Pyrite: 3D crystal surface (Peru)

Based on his long experience sourcing and cutting Pyrite, Stefan also developed a unique Pyrite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Pyrite material from low-quality material and avoid wasting your money on bad quality.

Purple Puddingstone

Pyrite Fusion

Based on his long experience sourcing and cutting Pyrite, Stefan also developed a unique Pyrite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Pyrite material from low-quality material and avoid wasting your money on bad quality.

Quantum Cuattro (Peru)

Based on his long experience sourcing and cutting Quantum Cuattro, Stefan also developed a unique Quantum Cuattro Gemstone Quality Standard, which helps you to distinguish jewelry-grade Quantum Cuattro material from low-quality material and avoid wasting your money on bad quality.

Red River Sunset®

Travertine (Peru)

Based on his long experience sourcing and cutting Red River Sunset travertine, an exclusive Stone of gemrock, Stefan also developed a unique Gemstone Quality Standard, which helps you to distinguish jewelry-grade Red River Sunset material from low-quality material and avoid wasting your money on bad quality.

Rhodonite (Peru)

Based on his long experience sourcing and cutting Rhodonite, Stefan also developed a unique Rhodonite Gemstone Quality Standard, which helps you to distinguish jewelry-grade Rhodonite material from low-quality material and avoid wasting your money on bad quality.

Rose Quartz (Peru)

Based on his long experience sourcing and cutting Rose Quartz, Stefan also developed a unique Gemstone Quality Standard, which helps you to distinguish jewelry-grade Rose Quartz material from low-quality material and avoid wasting your money on bad quality.

Rosophia (Peru)

Based on his long experience sourcing and cutting Peruvian Rosophia, Stefan also developed a unique Gemstone Quality Standard, which helps you to distinguish jewelry-grade Rosophia material from low-quality material and avoid wasting your money on bad quality.

Rhyolite

Rutilated Quartz (Peru)

Schillerstein

Semper Fi (Peru)

Based on his long experience sourcing and cutting Peruvian Semper Fi, Stefan also developed a unique Gemstone Quality Standard, which helps you to distinguish jewelry-grade Semper Fi material from low-quality material and avoid wasting your money on bad quality.

Serpentinite (Peru)

Based on his long experience sourcing and cutting Peruvian Serpentinite, Stefan also developed a unique Gemstone Quality Standard, which helps you to distinguish jewelry-grade Semper Fi material from low-quality material and avoid wasting your money on bad quality.

Tenorite (Peru)

Tiger Eye

Tourquoise

Thulite (Norway)

Tourmaline in Quartz (Peru)

Based on his long experience sourcing and cutting Tourmaline in Quartz, Stefan also developed a unique Tourmaline in Quartz Gemstone Quality Standard, which helps you to distinguish jewelry-grade Tourmaline in Quartz material from low-quality material and avoid wasting your money on bad quality.

Unakite (Peru)

Based on his long experience sourcing and cutting Peruvian Serpentinite, Stefan also developed a unique Gemstone Quality Standard, which helps you to distinguish jewelry-grade Semper Fi material from low-quality material and avoid wasting your money on bad quality.

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