  Photophoresis is a physical process that transports particles in optical thin
parts of protoplanetary disks, especially at the inner edge and at the
optically surface. To model the transport and resulting effects in detail, it
is necessary to quantify the strength of photophoresis for different particle
classes as a fundamental input. Here, we explore photophoresis for a set of
chondrules. The composition and surface morphology of these chondrules was
measured by X-ray tomography. Based on the three-dimensional models, heat
transfer through illuminated chondrules was calculated. The resulting surface
temperature map was then used to calculate the photophoretic strength. We found
that irregularities in particle shape and variations in composition induce
variations in the photophoretic force. These depend on the orientation of a
particle with respect to the light source. The variations of the absolute value
of the photophoretic force on average over all chondrules is $4.17\%$. The
deviation between the direction of the photophoretic force and illumination is
$3.0^\circ \pm 1.5^\circ$. The average photophoretic force can be well
approximated and calculated analytically assuming a homogeneous sphere with a
volume equivalent mean radius and an effective thermal conductivity. We found
an analytic expression for the effective thermal conductivity. The expression
depends on the two main phases of a chondrule, and decreases with the amount of
fine-grained devitrified, plagioclase-normative mesostasis up to factor of
three. For the chondrule sample studied (Bjurb\"ole chondrite), we found a
dependence of the photophoretic force on chondrule size.
