A zirconia light is an intensely brilliant chemical light produced by incandescent zirconia. It is similar in design to the Drummond light (limelight), but uses a block of zirconia instead of quicklime. Both have been replaced by the electric light.
Source This article incorporates text from a publication now in the public domain: Wood, James, ed. (1907). "Zirconia Light". The Nuttall Encyclopædia. London and New York: Frederick Warne.
References no author listed (1870)."New Zirconia Light", The Pharmaceutical Journal and Transactions. 29:81-82