Bumblebee Jasper

Hardness: 3.5-4.5 (Mohs scale), Color: Vibrant yellow, orange, black, and white bands, Luster: Waxy to subvitreous, Crystal structure: Microcrystalline/Aggregates. Often highly porous.

Formed in fumaroles (volcanic vents) in West Java, Indonesia. It is a sedimentary rock (travertine) chemically precipitated from hot springs and heavily influenced by volcanic emissions.

Primarily used in lapidary arts for cabochons, jewelry, and ornamental carvings due to its striking patterns.

Despite its name, it is not a true jasper (chalcedony/quartz) but mostly calcite. The vivid yellow/orange colors come from realgar (an arsenic sulfide), while black bands are usually pyrite or manganese oxide. Due to the arsenic content, rough material should be handled with care, though polished pieces are generally safe.

Identify by its distinctive black, yellow, and orange banding, relative softness compared to true jasper, and reaction to dilute acid (effervescence due to calcite). Exclusively found at Mount Papandayan, Indonesia.