Ulexite (Etimine)
A standard material in Glazecalc's library: its oxide analysis, unity contribution and hazards.
What it is
- Kind
- Boron sources
- Formula
- NaCaB₅O₉•8H₂O (ideal: Na₂O 7.65, CaO 13.84, B₂O₃ 42.95, LOI 35.55)
- Also called
- Ulexite, Ground Ulexite, Ulexit, Улексит, Sodium calcium pentaborate octahydrate, Boronatrocalcite, Ulexite (Etimine ground)
- Made by
- Eti Maden (Turkey), sold by Etimine USA Inc. and Etimine S.A.
- Sold in
- EU, US
- Source
- Etimine USA, Ulexite product page, typical analysis (Powder) (2026-02)
Commercial Turkish sodium-calcium borate ore, sold ground (75 and 45 micron grades); a raw boron source used mainly by European and Russian potters and in home-made Gerstley Borate substitutes. It is slightly soluble and loses about a third of its weight on firing.
Oxide analysis and unity formula
Glazecalc has the analysis of Ulexite (Etimine) as weight percent of the raw material. The unity contribution is the moles of each oxide in the amount of Ulexite (Etimine) that holds 1.0 mole of flux, which is how Glazecalc adds it into a recipe's unity formula.
| Oxide | Weight % | Unity contribution |
|---|---|---|
| B₂O₃ | 37 | 1.233 |
| CaO | 18 | 0.745 |
| Na₂O | 4 | 0.150 |
| SiO₂ | 3 | 0.116 |
| Al₂O₃ | 0.1 | 0.002 |
| SrO | 0.6 | 0.013 |
| MgO | 1.6 | 0.092 |
| Fe₂O₃ | 0.02 | 0.000 |
- Equivalent weight
- 232.01
- Fired weight
- 152.2
- Loss on ignition
- 34.4%
The equivalent weight is the grams of Ulexite (Etimine) that hold 1.0 mole of flux. The fired weight is what is left of that after firing.
Hazards and safety
Hazards: Borate: do not ingest; high-dose animal studies of inorganic borates show reproductive/developmental effects (U.S. Borax Gerstley Borate MSDS, Apr 2013). Avoid breathing dust. Etimine's SDS (rev. Oct 2021) lists it as not classified under UN GHS.
Use it in a recipe
Add Ulexite (Etimine) to a recipe in the Glazecalc calculator to see what it does to a glaze's unity formula.