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Gerstley Borate Original

SKU
GERSTLEY-BORATE
$7.51 Per Pound
  • Buy 1 for $7.37 each and save 1.9%

Gerstley Borate Original

GERSTLEY BORATE (real) A sodium-calcium-borate compound used as a low and mid-range glaze flux. This is a conglomerate mineral made up primarily of Colemanite, Ulexite and Hectorite. 

One Price for under full bags, 25% off for 50 pounds and up.

Gerstley is a natural borate similar to but not interchangeable with Colemanite on a 1 to 1 basis.

As of 11/5/2025 Laguna tells us we ordered Gerstley Borate Original so that's what we have today.

Laguna clay reported the mine is CLOSED they had  3000 tons or 6,000,000 pounds as of 6/18/2011

Quantity2331.4049 OR

Typical analysis:

  • B2O3    26.80%
  • CaO    19.40%
  • SiO2    14.80%
  • NaO2    3.95%
  • MgO    3.54%
  • Al2O3    0.98%
  • Fe2O3-T    0.425%
  • K2O    0.399%
  • P2O5    0.053%
  • TiO2    0.05%
  • MnO    0.024%
  • Trace minerals    0.079%
  • LOI    29.50%

Laguna clay reported the mine is CLOSED they had  3000 tons or 6,000,000 pounds as of 6/18/2011

If substituting Colemanite for GERSTLEY, use 1/2 as much Colemanite as GERSTLEY and add 1% CaCO3. If substituting GERSTLEY for Colemanite, use twice as much GERSTLEY. Minimum order quantity is 1 lb. (Gerstley-Borate)

Brand
Laguna

Warning WARNING: This product can expose you to chemicals including Silica, crystalline (airborne particles of respirable size), which are known to the State of California to cause cancer.  For more information go to www.P65Warnings.ca.gov.