The Spectrum Glaze Crystals melt and flow during the firing.  The Spectrum Glaze Crystals resemble small dry colored rocks in the raw form, and can be mixed with the glaze, or applied after the last coat of brushing glaze before the glaze has dried.  For the sample chips shown below, the Spectrum Glaze Crystals were applied to a flat tile with either clear or black glaze and fired to either Cone 05 or Cone 6 to achieve the displayed results.  The Spectrum Glaze Crystals can be fired on vertical pieces if care is taken so that the flow of the crystal will not escape (flow) off the piece.
    The 1 ounce bottle of Spectrum Glaze Crystals are typically enough of the crystals for more than a pint of glaze.
    Spectrum Crystals, while lead-free and nontoxic, should NEVER be considered for dinnerware usage.  The Crystal may cause stress in the glaze surface which could cause crazing (small spider web cracks in the glaze surface) that would harbor food particles and bacteria.