6.75 ct ANTIMONY – USA

Antimony

Antimony is a gemstone of metallic mystery and ancient allure. A native element, it represents the pure, uncombined state of a semi-metal that has been known to humanity for millennia. I have always been drawn to its “liquid-mercury” appearance; it typically presents in tin-white to lead-grey masses or rare, distinct rhombohedral crystals with a brilliant, metallic luster. It is a stone of the high-temperature hydrothermal veins, often found in association with its more famous sulfide, Stibnite. For the collector, native Antimony is a prize of elemental purity—a dense, heavy, and brilliantly reflective specimen that stands as a testament to the Earth’s ability to concentrate rare semi-metallic elements in their most primitive form.

The Heritage & Discovery

Historical Significance: Antimony has a history that stretches back to the dawn of civilization. Historically, its sulfide form was used as “kohl” eye makeup in Ancient Egypt, but the native metal was a prized rarity for early alchemists who associated it with the “gray wolf” due to its ability to “consume” other metals in alloys. In the world of fine minerals, native Antimony is celebrated as a “Type I” elemental mineral. It represents the transition between the metallic elements like Silver and the semi-metals like Arsenic. It stands as a symbol of transformation and structural stability, bridging the gap between ancient metallurgical practices and modern semiconductor science.

Discovery: While its compounds were known since at least 3000 BCE, the recognition of Antimony as a distinct element was solidified in the 17th century. Scientifically, it is a metalloid. Its discovery in its native form in the silver mines of Sala, Sweden, provided mineralogists with the first clear look at the element in its uncombined state. This understanding was vital for early chemistry, allowing scientists to isolate the properties of the metal from its more common ores.

Important Mines: The legendary and type-locality for world-class native Antimony is Sala, Västmanland, Sweden. I also have a high regard for the spectacular, large masses found in the Allemont region of France and the rare, crystalline specimens from the Lake George Mine in New Brunswick, Canada. For the vault, I prioritize the Swedish material for its historic pedigree and the Canadian specimens for their occasional, sharp crystal habits and exceptional metallic brilliance.

Mineralogical Profile

Description: Antimony is a native element and semi-metal that crystallizes in the trigonal system. It sits at a 3 to 3.5 on the Mohs scale, making it a relatively soft and brittle mineral that should be handled with care to avoid scratching its high-luster surfaces. It is characterized by its brilliant metallic luster and its tin-white color, which can develop a dark grey tarnish over time if exposed to air.

One of its most identifying traits is its perfect basal cleavage and its high density (6.6 to $6.7 g/cm³), which gives even small pieces a surprising “heaviness” in the hand. It has a high reflectivity, almost like a mirror, when fresh. Because it is a metalloid, it is a poor conductor of heat and electricity compared to true metals like Copper or Silver. When I select a piece for the collection, I look for “fresh” surfaces that haven’t been dulled by oxidation, as these highlight the sophisticated, “liquid-metal” look that makes native Antimony a standout for the systematic collector. It is a dense, grounding mineral that offers a unique, primeval beauty unlike any other elemental species.

Chemical Formula: Sb