no. 4 



TEKTITE SPECIMENS — CLARKE AND CARRON 



II 



mens are essentially the same with the exception of boron, lead, beryl- 

 lium, and yttrium. The high boron and beryllium contents are un- 

 doubtedly due to contamination. The mortar in which the Martha's 

 Vineyard tektite was ground had previously been used for grinding 



Table 3. — Semiquantitative spectrographic analysis ' of the Georgia and 



Martha's Vineyard tektites 



Martha's Vineyard 

 Georgia tektite » tektite b 



Element percent percent 



Si M M 



Al 7 7 



Fe i-5 1.5 



Mg 0.3 0.3 



Ca 0.3 0.3 



Na 0.7 0.7 



K 1.5 1.5 



Ti 0.15 0.3 



Mn 0.07 0.07 



Ag 0.00007 0.00007 



B 0.003 0.015 



Ba 0.03 0.03 



Be 0.0003 0.003 



Co 0.0015 0.0015 



Cr 0.0007 0.0007 



Cu 0.0007 0.0007 



Ga 0.0003 0.0003 



Nb 0.0015 0.0007 



Ni 0.0015 0.0015 



Pb 0.00015 0.007 



Sc 0.0007 0.0007 



Sn 0.0007 0.0007 



Sr 0.007 0.007 



V 0.007 0.007 



Y 0.0015 0.007 



Yb 0.00015 0.00015 



Zr 0.015 0.015 



« Figures are reported to the nearest number in the series 7, 3, l.S, 0.7, 0.3, 0.15, etc., in 

 percent. These numbers represent midpoints of group data on a geometric scale. Comparison 

 ot this type of data with that obtained by quantitative methods shows that the assigned group 

 includes the quantitative value about 60 percent of the time. 



6 Analyst: Helen W. Worthing, U. S. Geological Survey. 



hambergite, Be 2 (OH)B0 3 , and this probably accounts for the high 

 values for these elements. The high lead and yttrium values could not 

 be accounted for. The following elements were looked for and not 

 found: As, Au, Bi, Cd, Ce, Dy, Er, Eu, Gd, Ge, Hf, Ho, In, Ir, La, 

 Li, Lu, Mo, Nd, Os, Pd, Pr, Pt, Re, Rh, Ru, Sb, Sm, Ta, Tb, Th, 

 Tl, Tm, W, Zn. Only elements to which the method is sensitive in 



