Bornite Value Guide

Bornite, famously nicknamed Peacock Ore, is a prized copper sulfide mineral celebrated for its vibrant iridescent tarnish that develops through surface oxidation. These specific specimens from Mexico, dated between 2020-2024, are highly collectible due to their intense metallic luster and striking displays of purple, blue, and gold hues.

What affects the value of Bornite?

• Intensity and variety of the iridescent colors across the surface of the specimen.
• Overall size and weight of the copper-iron-sulfur mineral mass.
• The presence of well-defined crystal structures versus massive or granular forms.
• The preservation of the tarnish layer, as excessive handling can dull the brilliant metallic finish.

How to Identify Bornite?

• Look for the signature 'peacock' iridescence featuring a spectrum of metallic blues, purples, and magentas.
• Verify the heavy weight characteristic of copper-rich minerals compared to common rocks.
• Check for a grayish-black to black streak when tested on an unglazed porcelain plate.
• Note the brittle tenacity and lack of distinct cleavage typical of authentic Bornite crystals.

History of Bornite

Bornite was first described in 1725 for an occurrence in the Ore Mountains of Saxony, Germany. It was named in 1845 after the Austrian mineralogist Ignaz von Born. It is an important copper ore and is highly sought after by collectors for its brilliant display of metallic blues, purples, and golds that form through surface oxidation.