no. 3624 METEORITES — MASON AND MAYNES, 7 



surrounded by brown limonitic staining, indicative perhaps of the 

 former presence of trace amounts of lawrencite. Chondrules can be 

 distinguished with the aid of a hand lens, but they are not prominent. 



In thin section under the microscope the meteorite is seen to be 

 highly chondritic, but the boundaries of the chondrules are frequently 

 ill defined and tend to merge with the groundmass. The grain size of 

 the groundmass is similar to that within the chondrules. Chondrules 

 range from 0.3 to 1.5 mm in diameter and are of diverse types. 

 Commonest are aggregates of euhedral olivine crystals in a dark gray 

 turbid matrix, probably a devitrified glass. Similar chondrules with 

 euhedral crystals of clinobronzite also occur. Other chondrules consist 

 of an aggregate of radiating platy or prismatic crystals of pyroxene. 

 Barred olivine chondrules — the bars being alternately olivine and 

 turbid gray devitrified glass — are not uncommon. The opaque min- 

 erals are interstitial to the chondrules. 



The density of this meteorite, reported by Neviani (1921), is 3.76. 



Table 2. — Chemical analysis and normative mineral composition of the Bur- 

 Gheluai meteorite (analysis: Maynes; norm: Mason) 



Sum 



99.90% 



Chemical composition. — The chemical analysis is given above 

 along with the normative mineralogical composition calculated ac- 

 cording to Wahl (1951). The composition is very similar to that of 

 the Allegan meteorite. Bur-Gheluai is an olivine-bronzite chondrite in 

 Prior's classification (1920), and the total iron content, 28.45 percent, 

 places it in the high-iron (H) group of Urey and Craig (1953). 



