Bidspirit auction | Polished Agate & Thunderegg Specimens

Polished Agate & Thunderegg Specimens - This lot consists of three natural history specimens including one thunderegg section and two agate slices, each featuring a professionally polished display face. The thunderegg specimen presents a reddish-brown rhyolite matrix with small dark inclusions surrounding a central core of waterline agate. This core displays horizontal layers of translucent light gray and opaque white chalcedony. The reverse side shows the natural, unworked yellowish-tan matrix typical of these geode-like formations. The first agate slice is teardrop-shaped, showing subtle concentric banding in shades of pale mint green and translucent white with a faint yellowish-orange tint toward the center, retained within a natural, jagged yellowish-brown matrix rind. The second agate slice is an elongated specimen featuring a large, opaque white crystalline center of feathered quartz surrounded by delicate concentric bands of translucent lavender-gray and white chalcedony. No maker marks, signatures, or locality labels are visible on any of the specimens. Thunderegg: 4 inches wide and 3.5 inches high. Green agate slice: 4.25 inches long and 2.25 inches wide. Crystalline agate slice: 5.25 inches long and 2.75 inches wide.