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Alternate Names: Cadycal Jan/00

Description: Precipitated Calcium Borate

Oxide Analysis Formula
CaO 26.00% 0.98
MgO 0.24% 0.01
B2O3 47.50% 1.45
Fe2O3 0.05% -
Na2O 0.10% -
SiO2 0.50% 0.02
Al2O3 0.10% -
SrO 0.03% -
K2O 0.01% -
LOI 25.00%n/a
SO3 0.50%n/a
H2O 1.00%n/a
Cl 0.07%n/a
Oxide Weight 158.10
Formula Weight 215.30


Cadycal was a calcium borate mineral produced by Fort Cady Minerals Corp of Newberry Springs, CA ( Their plant was in the same area as US Borax and other boron producers. The ore body from which Cadycal was made is 1400 feet below the surface. The mining was done by drilling wells into the ore body and pumping down a solution of diluted sulfuric acid. The resulting boric acid was pumped to the surface and reacted with lime to produce a pure calcium borate that was dried and packaged. Like Gerstley Borate, Cadycal did have some particulate lime material (depending on the quality of the lime used in the process).

Cadycal contained much more boron than Gerstley Borate and had a different mix of auxiliary oxides so it was not a chemical equivalent. It was not plastic and did not impart any creamy consistency, dry hardness, or suspension properties to glaze slurries. It was a great candidate to make up part of the recipe for a substitution for GB because its chemistry was so similar to Colemanite, a mineral portion of GB. Cadycal was an exceptionally good melter at low temperatures, it was already very fluid by cone 06. Amazingly, although Cadycal had a higher boron content than Ulexite, the latter melted one or two cones earlier.

During the development of Boraq we actually flew to California to visit this facility south of Barstow.

The analysis shown here was provided by Fort Cady in May 2003.

Related Information


Materials Colemanite
A natural source of boron that melts at a very low temperature.
Typecodes Flux Source
Materials that source Na2O, K2O, Li2O, CaO, MgO and other fluxes but are not feldspars or frits. Remember that materials can be flux sources but also perform many other roles. For example, talc is a flux in high temperature glazes, but a matting agent in low temperatures ones. It can also be a flux, a filler and an expansion increaser in bodies.
URLs - The best place for info on Gerstley Borate


Bulk Density lbs/cu. ft. (Packed) 47
Sieve Analysis Dry +60 mesh: ~0.3% +200: ~15% +325: ~35%
By Tony Hansen
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