Jepara, Strange Indonesia Pallasite Meteorite, Micromount


On May 08, 2008, workers unearthed a massive rock from muddy ground on the island of Java in Indonesia. The unusual boulder was analyzed and was identified as a terrestrialized pallasite (main group) that has undergone extensive alteration from oxidation. The metal matrix has been mostly reduced to oxides, but the olivines still appear fresh in contrast. The olivines can be quite large and multiple colors are seen, including yellow, green, orange, and shades in between. Although very oxidized, the beautiful olivines and unusual aesthetic of this meteorite make it unique in appearance.

Refer to the photo. The black centimeter cube is shown for scale and is not included. You are purchasing a single small olivine crystal similar to the one shown. Your purchase will include a labeled gemjar for safe storage.

From the Meteoritical Bulletin entry on Jepara :

Jepara 6°36’S, 110°44’E

Java, Indonesia

Found: May 2008

Classification: Pallasite (Main group)

History: Anonymous finders recovered the meteorite specimen in 2008 during excavation activities in muddy ground.

Physical characteristics: The original mass of the meteorite boulder was 499.5 kg. It is spherically shaped with the shortest and longest diameter of 70 cm and 85 cm, respectively. The crust is weathered and rusty.

Petrography: The interior shows a homogeneous distribution of coarse-grained rounded olivine grains (6 to 12 mm). The groundmass is composed of secondary magnetite, nickel sulfide and sulfate (nickel hexahydrite), and primary schreibersite. Modal abundances are olivine (64 vol%), magnetite (23 vol%), nickel sulfide and sulfate (8 vol%), and schreibersite (5 vol%).

Geochemistry: Olivines are homogeneous in composition (Fa12-13). Sulfide is composed of NiS and may represent a replacement product of troilite, while magnetite (Fe3O4) is a weathering product of primary FeNi phases. Schreibersite has the composition (Fe1.85Ni1.15)P. Replicate analyses of oxygen isotopes were made on acid-washed samples by laser fluorination at UGött (A. Pack): δ17O (SMOW) 1.862, 1.367, 1.380; δ18O (SMOW) 3.820, 3.011, 3.160; and Δ17O -0.130 -0.200, -0.280 (all per mil).

Classification: Main group pallasite, extensively weathered, fresh olivine

Specimens: Type specimens of 230 g and 20 g with surface areas of 190 cm2 and 20 cm2, respectively, and one thin section are on deposit at UJena. An anonymous owner holds the main mass.