WE PROPOSE TRANSFORMATIVE OBSERVATIONS OF MAIN BELT ASTEROIDS IN SCATTERED LIGHT WITH GROUND-BASED OPTICAL POLARIMETRY. LINEAR POLARIZATION HAS BEEN SHOWN TO BE ANTICORRELATED WITH ALBEDO ON THE SURFACES OF MERCURY THE MOON AND MARS. SINCE POLARIMETRY IS A DIFFERENTIAL QUANTITY (RATIO OF POLARIZED TO TOTAL FLUX) IT IS INSENSITIVE TO ROTATIONAL CHANGES IN CROSS-SECTIONAL AREA WHICH ARE PRESENT FOR ASTEROIDS (SO-CALLED SHAPE CHANGES ). POLARIZATION VARIATIONS CAN THEREFORE BE TRACED TO SURFACE ALBEDO VARIATIONS. IN CONTRAST BOTH SHAPE CHANGES AND ALBEDO VARIATIONS MANIFEST IN PHOTOMETRY. CONVENTIONAL POLARIMETRY IS LIMITED BY WAVEPLATES WHICH ARE INCAPABLE OF ACCURACY BELOW THE ~0.01% = 100 PPM LEVEL (PARTS-PERMILLION) DUE TO LINEAR TO CIRCULAR POLARIZATION CONVERSION IN THE OPTIC. DUE TO THIS LIMITATION CHANGES IN LINEAR POLARIZATION WITH ROTATIONAL PHASE ARE ONLY CONCLUSIVELY DETECTABLE WITH WAVEPLATE POLARIMETERS FOR ASTEROID (4) VESTA. HOWEVER THE UNIQUE PHOTOELASTIC MODULATORS (PEMS) IN THE POLISH2 POLARIMETER (WIKTOROWICZ&NOFI 2015) ENABLE PHOTON-LIMITED ACCURACY AT THE 1 PPM LEVEL. THIS INSTRUMENT HAS NOT ONLY CONFIRMED ROTATIONAL POLARIZATION OF (4) VESTA BUT IT HAS ALSO DETECTED THIS EFFECT IN (1) CERES AND (7) IRIS WITH HIGH SIGNIFICANCE. THUS POLISH2 HAS ALREADY TRIPLED THE NUMBER OF ASTEROIDS WITH KNOWN ALBEDO VARIATIONS DETECTABLE WITH POLARIMETRY AND HAS OBSERVED THIS EFFECT ON ALL THREE ASTEROIDS IN OUR PILOT STUDY. IN ADDITION THE POLISH2 PEMS ENABLE SIMULTANEOUS MEASUREMENT OF LINEAR AND CIRCULAR POLARIZATION WHICH MAY RESULT FROM MULTIPLE SCATTERING BY ROUGH REGOLITH OR BY PHASE RETARDANCE FROM METALLIFEROUS SURFACES. POLISH2 HAS DISCOVERED BROADBAND CIRCULAR POLARIZATION ON (7) IRIS WHICH IS THE FIRST DETECTION OF CIRCULAR POLARIZATION IN AN ASTEROID AND WEAK ANTICORRELATION OF LINEAR POLARIZATION WITH CIRCULAR POLARIZATION ON (1) CERES AND (4) VESTA. BRIGHT REGIONS ARE EXPECTED TO PROVIDE LOW LINEAR POLARIZATION BUT DETECTABLE CIRCULAR POLARIZATION DUE TO MULTIPLE SCATTERING. WE PROPOSE TO A) VERIFY LINEAR POLARIZATION VARIATIONS AND CIRCULAR POLARIZATION RESULTS ON (1) CERES (4) VESTA AND (7) IRIS; B) OBSERVE SIX BRIGHT MAIN BELT ASTEROIDS FOR LONGITUDE-DEPENDENT LINEAR POLARIZATION VARIATIONS AND FOR CIRCULAR POLARIZATION; AND C) OBSERVE THREE ASTEROIDS WITH HIGH RADAR ALBEDO TO SEARCH FOR CIRCULAR POLARIZATION FROM THEIR METALLIFEROUS SURFACES. WE THEREFORE PROPOSE TO SEARCH FOR ALBEDO VARIATIONS WITH LONGITUDE ON TWELVE ASTEROIDS AND TO IDENTIFY THE SIGNATURES OF MULTIPLE SCATTERING AND METALLIFEROUS PHASE RETARDANCE ON THEIR SURFACES.