This is one of the fragments of the meteorite of Chelyabinsk. At 9:22 a.m. (local time) on February 15, 2013, a bright fireball was seen by numerous residents in parts of the Kurgan, Tyumen, Ekaterinburg and Chelyabinsk cities. This superbolide meteor descended at over 55,000 Km/h over the Ural Mountains, exploding at an altitude of 25-30 km.
These fragments are ordinary chondrite meteorites and contain 10% iron. The Chelyabinsk meteorite was later determined to come from the LL chondrite group (LL5). The majority of the stones are composed of a light-colored lithology with a typical chondritic texture. Chondrules (~63%) are readily delineated and set within a fragmental matrix. The chondrule glass is devitrified. The main phases are olivine and orthopyroxene. Rare grains of augite and clinobronzite are present. In this sample we can observe perfectly chondrules and fusion crust. Very representative and good sized sample (5.08 grams / 0.18 oz).
More info on the website of the Meteorical Society.

State/Prov/County: Chelyabinskaya oblast'  -  Date: 15 Feb 2013; 3:22 UT -  Coordinates: 54°49'N-61°07'E
Mass: >100 kg - Pieces: many - Class: LL5 - Shock stage: Moderated S4 - Weathering grade: W0