THE GEMHOOD EDITORIAL LIBRARY
Ulexite gemstone guide
Ulexite — hydrated sodium calcium borate mineral, sometimes called TV rock. Read about characteristic appearance, Mohs hardness, safety and care.
Gem facts · Quality considerations · Care & meaning
A study in colour and character
Every shade has a story.
Typical appearances for Ulexite. Natural stones vary, and lighting or treatment can change their appearance.
Where Ulexite is found
Boron, California, United States; Iquique, Chile; and evaporite deposits in the Andes
United States
Chile
How it forms
Forms in evaporite deposits and borate-rich lake sediments, commonly as fibrous aggregates or massive beds.
These are representative geological or commercial sources, not certified provenance for an individual stone. Country of origin should be substantiated independently when relevant to value.
01 / THE GEM AT A GLANCE
What is Ulexite?
Ulexite is hydrated sodium calcium borate mineral, sometimes called TV rock, commonly represented by the formula NaCaB₅O₆(OH)₆·5H₂O. Mohs hardness: 2.5. Reported colours include White to colourless, sometimes grey or cream from inclusions. Forms in evaporite deposits and borate-rich lake sediments, commonly as fibrous aggregates or massive beds. Parallel silky white fibres that can transmit an image across a polished slice—its natural fibre-optic “television stone” effect.
Composition: NaCaB₅O₆(OH)₆·5H₂O. Scientific properties apply to the mineral or gem type, not as a guarantee about an untested individual product.
Ulexite is hydrated sodium calcium borate mineral, sometimes called TV rock, commonly represented by the formula NaCaB₅O₆(OH)₆·5H₂O. Mohs hardness: 2.5. Reported colours include White to colourless, sometimes grey or cream from inclusions. Forms in evaporite deposits and borate-rich lake sediments, commonly as fibrous aggregates or massive beds. Parallel silky white fibres that can transmit an image across a polished slice—its natural fibre-optic “television stone” effect. Characteristic features: Parallel silky white fibres that can transmit an image across a polished slice—its natural fibre-optic “television stone” effect. Documented occurrences include Boron, California, United States; Iquique, Chile; and evaporite deposits in the Andes. Localities describe geological reports, not the proven origin of any individual sale item. Named for chemist Georg Ludwig Ulex and valued as a demonstration of naturally parallel optical fibres. Collector material and educational optical demonstration rather than scratch-resistant jewellery. Keep dry, avoid prolonged soaking, heat, scratching and polishing; do not confuse with stronger quartz or selenite. A true optic-fibre effect depends on aligned fibres, not on externally printed logos or imitation plastics. Fragile and water-sensitive in practical handling; do not ingest, powder or immerse as a wellness material. Specialist testing and chain-of-custody evidence matter for high-value or hazardous materials. Genuine mineral identification requires evidence beyond colour or the appearance of a picture. Read the complete guide before acquiring a specimen.
02 / LOOK CLOSER
Colour, appearance and quality
Characteristic features: Parallel silky white fibres that can transmit an image across a polished slice—its natural fibre-optic “television stone” effect. Documented occurrences include Boron, California, United States; Iquique, Chile; and evaporite deposits in the Andes. Localities describe geological reports, not the proven origin of any individual sale item.
Before you choose a stone
Compare images taken in more than one lighting condition, ask for views of the actual item and check how the cut and setting change its appearance. A gemstone type is not a standard grade: each natural specimen has its own colour, inclusions and workmanship.
THE GEMHOOD BUYER'S FIELD NOTES
How to choose Ulexite: three checks
- 01
A true optic-fibre effect depends on aligned fibres, not on externally printed logos or imitation plastics.
- 02
Keep dry, avoid prolonged soaking, heat, scratching and polishing; do not confuse with stronger quartz or selenite.
Fragile and water-sensitive in practical handling; do not ingest, powder or immerse as a wellness material.
Collector material and educational optical demonstration rather than scratch-resistant jewellery.
These notes describe typical gem material and trade practices. They do not independently grade or identify a specific item offered for sale.
03 / BUY WITH CONFIDENCE
Natural, laboratory-grown, treated or imitation?
A true optic-fibre effect depends on aligned fibres, not on externally printed logos or imitation plastics. Fragile and water-sensitive in practical handling; do not ingest, powder or immerse as a wellness material. Specialist testing and chain-of-custody evidence matter for high-value or hazardous materials.
These distinctions should be clear in the listing for any particular gem. Treatments are not automatically unacceptable, but an undisclosed treatment, vague mineral identity or unsupported origin claim prevents an informed purchase. Where material identity materially affects value, an independent gemological identification report may be worth considering.
A CLOSER LOOK
Formation and mineral chemistry
Forms in evaporite deposits and borate-rich lake sediments, commonly as fibrous aggregates or massive beds.
Ulexite is hydrated sodium calcium borate mineral, sometimes called TV rock, commonly represented by the formula NaCaB₅O₆(OH)₆·5H₂O. Mohs hardness: 2.5. Reported colours include White to colourless, sometimes grey or cream from inclusions. Forms in evaporite deposits and borate-rich lake sediments, commonly as fibrous aggregates or massive beds. Parallel silky white fibres that can transmit an image across a polished slice—its natural fibre-optic “television stone” effect.
A CLOSER LOOK
Diagnostic features and lookalikes
Parallel silky white fibres that can transmit an image across a polished slice—its natural fibre-optic “television stone” effect.
A true optic-fibre effect depends on aligned fibres, not on externally printed logos or imitation plastics.
A CLOSER LOOK
Representative origins and provenance
Boron, California, United States; Iquique, Chile; and evaporite deposits in the Andes
A locality reference does not prove the offered specimen originates there.
A CLOSER LOOK
Uses and jewellery suitability
Collector material and educational optical demonstration rather than scratch-resistant jewellery.
Fragile and water-sensitive in practical handling; do not ingest, powder or immerse as a wellness material.
A CLOSER LOOK
Cleaning, handling and storage
Keep dry, avoid prolonged soaking, heat, scratching and polishing; do not confuse with stronger quartz or selenite.
Named for chemist Georg Ludwig Ulex and valued as a demonstration of naturally parallel optical fibres.
A CLOSER LOOK
Specimen image attribution and reuse licence
Specimen image adapted from 'Ulexite - USGS Mineral Specimens 1130.jpg' by Andrew Silver / USGS (public domain) on Wikimedia Commons. Licence: Public domain (USGS). Photo has been resized, converted to WebP and presented against a white background.
Original source: https://commons.wikimedia.org/wiki/File:Ulexite_-_USGS_Mineral_Specimens_1130.jpg ; licence text: https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits. The image licence applies to this derivative, not the entire GemHood website.
04 / WEAR IT WELL
Ulexite in jewellery
Collector material and educational optical demonstration rather than scratch-resistant jewellery.
05 / MAKE IT LAST
How to care for Ulexite
Keep dry, avoid prolonged soaking, heat, scratching and polishing; do not confuse with stronger quartz or selenite.
One essential care distinction
Mohs hardness describes resistance to scratching, not resistance to breaking. Gemstones with cleavage, existing fractures, porous surfaces or fillings can need extra care regardless of their hardness number. If you do not know whether a piece has been treated, begin with the gentlest appropriate cleaning method.
06 / CULTURE & MEANING
History, heritage and symbolism
Named for chemist Georg Ludwig Ulex and valued as a demonstration of naturally parallel optical fibres.
Traditional meanings and spiritual associations are part of cultural storytelling. They are not evidence that a gemstone diagnoses, prevents or treats any medical condition.
GOOD QUESTIONS, CLEAR ANSWERS
Ulexite FAQs
What is Ulexite?
Ulexite is hydrated sodium calcium borate mineral, sometimes called TV rock, commonly represented by the formula NaCaB₅O₆(OH)₆·5H₂O. Mohs hardness: 2.5. Reported colours include White to colourless, sometimes grey or cream from inclusions. Forms in evaporite deposits and borate-rich lake sediments, commonly as fibrous aggregates or massive beds. Parallel silky white fibres that can transmit an image across a polished slice—its natural fibre-optic “television stone” effect.
What is the Mohs hardness of Ulexite?
2.5; scratch hardness does not measure toughness or safety.
Where is Ulexite found?
Boron, California, United States; Iquique, Chile; and evaporite deposits in the Andes. Individual provenance must be independently verified.
Is Ulexite suitable for jewellery?
Collector material and educational optical demonstration rather than scratch-resistant jewellery.
How should I store and clean Ulexite?
Keep dry, avoid prolonged soaking, heat, scratching and polishing; do not confuse with stronger quartz or selenite.
How can I identify genuine Ulexite?
A true optic-fibre effect depends on aligned fibres, not on externally printed logos or imitation plastics.
What safety or treatment issues affect Ulexite?
Fragile and water-sensitive in practical handling; do not ingest, powder or immerse as a wellness material.
A NOTE FROM THE GEMHOOD EDITORIAL DESK
How to use this guide
We explain gemstone properties, known mining regions and customary treatments to help you shop more confidently. Each gemstone can vary in quality and individual provenance, so compare the actual jewellery listing and request supporting documentation if origin, treatment or natural-versus-laboratory-grown status affects your choice.
Our gemstone library is educational and does not act as a laboratory identification certificate. Independent gemological assessment is advisable for valuable or disputed claims.
EDITORIAL REFERENCES
Research and further reading
References describe mineral species and representative occurrences, not verification of any individual item for sale.
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Compare Ulexite with similar gemstones
These stones can overlap in colour, appearance or jewellery use. The mineral identity, treatments and durability may be very different.
KEEP EXPLORING
Other gemstones to discover
Educational articles describe gemstone types and common trade practices. They are not individual gemological certificates, current price appraisals or medical advice.