Toconao 001        22°58.68’S, 68°18.01’W

Antofagasta, Chile

Find: 26 Mar 2019

Classification: Ordinary chondrite (LL3)

History: The meteorite was found by Mr. T. Kryachko on March 26, 2019, during a visual search for the meteorites in the Atacama desert.

Physical characteristics: The meteorite shows numerous fragments of irregular shape. It is grayish-brown in color, with fusion crust is absent, and chondritic texture visible on the sample surface. Some of the fragments are patchy, covered by salts; some of them are fractured by sub-parallel fracture planes due to weathering processes.

Petrography: (Lorenz C. A.) The meteorite is composed of chondrules of RP, RO, BP, BO, POP, PO and C types. Average chondrule diameter is 486±290 µm (N=280). Minor components are chondrule fragments, mineral grains and essentially fine-grained, non-transparent matrix. The chondrules are well outlined and have sharp contacts with the matrix. Troilite-rich chondrules are widely distributed, silica-rich chondrule was found. The main phases are olivine, pyroxene, troilite and glass; metal is accessory. Several chondrules contain Al-rich clinopyroxene. Olivine has sharp optical extinction. A network of thin veins of weathering products crosses the meteorite.

Geochemistry: Mineral compositions and geochemistry: Olivine: Fa_19.4±12.3 (N=70), PMD Fa is 63.2%, CaO 0.01-0.58 wt%; pyroxene Fs_8.3±7.6Wo_1.2±1.2 (N=30), clinopyroxene Fs_15.4±6.1Wo_23.4±8.2 (N=6); Al-rich clinopyroxene (wt%, N=22): Al₂O₃ 13.7±4.3; TiO₂ 0.7±0.4; Cr₂O₃ 0.3±0.3; sulfide is troilite; Total Fe of the meteorite is 19.7 wt% (XRF, T. G. Kuzmina, Vernad).

Classification: Based on a texture, PMD of Fa olivine and total Fe abundance the meteorite is classified as ordinary chondrite of LL group, petrological type 3.

Specimens: Type specimen of 158 g and thin section are on deposit in Vernad. Mr. T. V. Kryachko holds main mass of the meteorite.