5.09 ct. German Proustite
Color: Dark Red
Clarity: Moderately Included
Origin: Marienberg Dist., Saxony, Germany
Cut: Cushion
Treatments: None
Measurements: 10.6 x 6.5 mm
One of the great gem rarities, faceted Proustite is almost unheard of outside of institutional collections. A silver sulfantimonide mineral, Proustite is well known for the stunning deep red color of crystals, along with its importance as a silver ore. As such, it is sometimes even referred to as 'ruby silver'. As a gem, it is quite a unique material - the color in many crystals can darken upon exposure to light so that the red can be difficult to see once the stone has been faceted. This makes for a stone that has an intense color but also a metallic luster - an extreme version of the visual effect of Cuprite. From the classic and rare German locality, this is a very large, historic example with a fine US cut. Not entirely clean but the color and luster remain unaffected - a fascinating gem indeed and essentially unobtainable.