Bumblebee Jasper

Bumblebee jasper is a striking yellow, orange and black banded stone from Indonesia, named for its wasp-like striping. Despite the name it is not a true jasper (it is not silica-based); it is a fine-grained volcanic sedimentary rock made largely of calcite and aragonite colored by sulfur, iron oxides and arsenic-bearing minerals.

The vivid yellow and orange bands come from sulfur and the arsenic sulfides realgar and orpiment, while the black areas are pyrite and other oxides. Because of these arsenic-bearing minerals, the stone should be handled and worked with care.

Its bold color makes it popular in jewelry, but its true composition sets it apart from ordinary chalcedony-based gem materials.

Bumblebee jasper forms in volcanic fumarole environments, originally documented around the Papandayan volcano area on Java, Indonesia. Hot, gas-rich solutions percolating through soft sedimentary and volcanic sediments deposit calcium carbonate along with sulfur and metal-bearing minerals.

As these fluids cool and react, sulfur, realgar (arsenic sulfide), orpiment, pyrite and hematite precipitate in successive layers, creating the bright yellow, orange and black banding. The matrix is dominated by calcite/aragonite rather than quartz.

This fumarolic, low-temperature sedimentary-volcanic origin explains its softness and its content of reactive sulfur and arsenic minerals, which differ sharply from true silica jaspers.

Look for bold, banded bright yellow and orange zones alternating with black and grey-white; the wasp-like yellow-and-black striping is unmistakable. The yellow can be almost neon.

Hardness is only about 5-6, notably softer than true jasper (7); it can be scratched more easily and may effervesce weakly where calcite is present. Luster is dull to waxy.

Look-alikes: true yellow jasper is harder (7) and silica-based; dyed agates are harder and lack the calcite matrix. Because bumblebee jasper contains arsenic sulfides, avoid inhaling its dust, wet-cut it, and wash hands after handling.

Bumblebee jasper is cut into cabochons, beads and pendants for its dramatic color, and it is popular in contemporary jewelry. Because it is relatively soft and contains arsenic minerals, lapidaries wet-cut it, avoid breathing the dust, and seal finished pieces.

Finished, polished stones set in jewelry are generally considered safe to wear, but raw material and dust require caution. It is mainly a decorative and collector stone rather than an industrial material.

Metaphysically it is associated with confidence, motivation and personal power, though these claims are traditional rather than scientifically supported.