\begin{table}%t1
\caption{\label{t1}Properties of the samples.}
%\centerline
 {
\begin{tabular}{c c c c c c c }
\hline\hline
Chem. formula & Mineralogical name & Product Info. & Abbr. & Size ($\mu$m) & Shape & Sect. \\
\hline
TiO     & Titanium monoxide & Aldrich           & TiO & 0.1--2.0         & irr. w/sharp edges           & A.1. \\
\hline
$\alpha$-TiO$_2$  & Rutile & Aldrich            & CR1 & 0.1--0.5         & irr. w/round. edges          & A.2. \\
$\alpha$-TiO$_2$  & Rutile & Alfa Aesar         & CR2 & 0.1--0.5         & irr. w/sharp \& round. edges & A.2. \\
$\alpha$-TiO$_2$  & Rutile & Tayca 150W         & CR3 & 0.01--0.08       & thin \& long                  & A.2.\\
$\alpha$-TiO$_2$ & Rutile  & Chitan Inc. No.101 & CR4 & 0.01--0.1        & sph. \& ellip.                & A.2.\\
$\beta$-TiO$_2 $ & Anatase & Alfa Aesar         & CA1 & 0.1--0.6         & round. edges                  & A.2. \\
$\beta$-TiO$_2 $ & Anatase & C.P.               & CA2 & 0.1--0.2         & round. \& squ. \& ellip.      & A.2. \\
$\beta$-TiO$_2 $ & Anatase & Tayca 600          & CA3 & 0.01--0.05       & round.                        & A.2. \\
$\beta$-TiO$_2 $ & Anatase & Chitan Inc. No.9   & CA4 & $\approx$0.05  & round. \& long-narrow         & A.2. \\
\hline
Ti$_2$O$_3$ & Dititanium trioxide & Alfa Aesar & Ti$_2$O$_3$ & 0.2--1.5  & irr. w/sharp edges         & A.3. \\
\hline
Ti$_3$O$_5$ & Trititanium pentoxide & Alfa Aesar & Ti$_3$O$_5$ & 0.1--1.0 & irr. w/sharp edges        & A.4. \\
\hline
CaTiO$_3$   & Perovskite    & Alfa Aesar    & CaTiO$_3$ & 0.03--0.5      & irr. w/sharp edges         & A.5. \\
\hline
Al$_2$TiO$_5$ & Tialite & Alfa Aesar   & Al$_2$TiO$_5$ & 0.05--0.6       & irr. w/very sharp edges    & A.6. \\
\hline
$\alpha$-Al$_2$O$_3$  & Corundum & Alfa Aesar & CAC1 & 0.3--0.5        & irr. w/round. edges          & A.7. \\
$\alpha$-Al$_2$O$_3$  & Corundum & Glaschemie Jena & CAC2 & 0.06--1.0  & irr. w/sharp edges           & A.7. \\
$\gamma$-Al$_2$O$_3$ & & Alfa Aesar & CG & 0.1--0.3                    & squ. w/round. edges          & A.7. \\
$\chi$-$\delta$-$\kappa$-Al$_2$O$_3$ & & C.P. & CCDK & 0.05--1.0       & irr. \& tabular               & A.7. \\
\hline
MgAl$_2$O$_4$ & Spinel & Alfa Aesar & CSp1 & 0.04--0.5                 & irr. w/sharp \& round. edges & A.8. \\
MgAl$_2$O$_4$ & Spinel & Aldrich    & CSp2 & $\approx$0.05           & sph.                          & A.8. \\
\hline
\end{tabular}}
\par
\medskip 
``C.P.'' $\rightarrow$ commercial product; ``irr.'' $\rightarrow$ irregular; ``round.'' $\rightarrow$ roundish; ``squ.'' $\rightarrow$ square; ``ellip.'' $\rightarrow$ ellipsoidal; ``sph.'' $\rightarrow$ spherical.
\end{table}