title: A carbonate-rich, hydrated, interplanetary dust particle: possible residue from protostellar clouds.
abstract: Transmission electron microscopy of a hydrated interplanetary dust particle (IDP) indicates that it contains abundant magnesium-iron carbonates, primarily breunnerite and magnesian siderite. This IDP displays a strong absorption band at 6.8 micrometers in its infrared spectrum, similar to that in certain protostellar spectra. The carbonates probably account for the 6.8-micrometer band in the IDP spectrum, suggesting that carbonate also may occur in interstellar dust and be the source of the controversial 6.8-micrometer feature from the protostellar spectra.
authors.forename: K
authors.initials: K
authors.lastname: Tomeoka
authors.forename: P R
authors.initials: PR
authors.lastname: Buseck