The crystal structure of the mineral boleite contains Cu2+ ions (each with S=1/2) forming truncated cube clusters of linked triangles. Susceptibility, neutron scattering and exact diagonalization calculations suggest that effective S=1/2 degrees of freedom emerge on the triangles, followed by condensation of these into a singlet state at lower temperature. We hypothesize that the resulting cube of effective S=1/2 degrees of freedom is a fragment of the full S=1/2 dimer problem on the cubic lattice, where a spin liquid groundstate exists. The clusters in boleite afford an intermediate situation, accessible to both experiment and exact diagonalization, in which a spin liquid "droplet" can be studied. Here we propose to characterize the wavevector and temperature dependence of the spin correlations.