Short answer: Tiffany stone is a trade name for purple, blue and white nodules from the beryllium mine at Spor Mountain in western Utah. It is a rock, not one mineral: mostly fluorite, with opal, chalcedony, quartz, carbonates and a few percent of the beryllium mineral bertrandite. It is soft for a cabochon, about Mohs 5 to 5.5, and almost all of it is crushed as ore, which is why polished pieces are scarce.
Where does Tiffany stone come from?
One place. Geology.com, in an article by gemologist Hobart King, states that it is mined at one location worldwide: the Brush Wellman beryllium mine at Spor Mountain, western Utah. It occurs there as nodules inside the ore, and those nodules typically contain between one and two percent beryllium by weight.
That makes Tiffany stone an accident of industrial mining. The mine exists for beryllium, a strategic metal. The U.S. Geological Survey describes beryllium as one of the lightest of all metals with one of the highest melting points of any light metal, used principally in aerospace and defense. USGS Professional Paper 1802-E puts Spor Mountain's importance bluntly: the current sole domestic source of beryllium is bertrandite ore from the Spor Mountain deposit in Utah (USGS Publications Warehouse). The same report notes that bertrandite is the source mineral for more than 90 percent of the beryllium produced globally.
Because the operator is in the beryllium business, nobody runs the nodules as a gem product. Geology.com reports that almost all of the Tiffany stone mined at Spor Mountain is crushed for beryllium, and that the rough reaching the market came out with employees or with collectors who were rarely allowed into the mine. That is the supply story behind every slab and tumble.
What is Tiffany stone made of?
Think of it as a replaced carbonate pebble. The USGS, as quoted by Geology.com, describes the nodules as carbonate clasts that have been largely replaced by fluorite. Bertrandite, the beryllium silicate Be4Si2O7(OH)2, sits inside the fluorite as submicroscopic grains, so the mineral that gives the ore its value is invisible to the eye.
| Component | What it contributes | Key data |
|---|---|---|
| Fluorite (CaF2) | The purple color, most of the bulk | Hardness 4, SG 3.18 |
| Opal and chalcedony | Creamy white to bluish zones, the "opalized" look | Silica, softer and harder zones mixed |
| Calcite, dolomite, quartz | Leftover and secondary filling | Calcite is acid-sensitive |
| Bertrandite | Beryllium content, not visible | Hardness 6 to 7, SG 2.60 |
The fluorite figures come from Webmineral's fluorite data, which lists a hardness of 4 and a specific gravity of 3.18. Webmineral's bertrandite page gives bertrandite a hardness of 6 to 7 and a specific gravity of 2.60. That mix explains how the stone behaves on the wheel: hard and soft patches sit side by side, and the softer fluorite areas can undercut during polishing, leaving a slightly uneven surface on lower-grade pieces.
Bertrandite is a minor player even in the ore. OSHA notes that bertrandite with under 1 percent beryllium is the principal mineral mined for beryllium in the U.S., while beryl, at 4 percent, is the main ore elsewhere.
Why is it called Tiffany stone, and what are its other names?
The name has no documented connection to the New York jeweler. Geology.com is explicit that the company has never been associated with the mine or with the stone, and that a story about a miner's daughter named Tiffany is possible but not found in any written record.
You will see several other labels on the same material:
- Opal fluorite or opalized fluorite. The most accurate names, since they describe what most specimens are actually made of.
- Ice cream stone or ice cream opal. A nickname for the swirled purple, cream and white patterns.
- Bertrandite. Common in listings and wrong as a description. Bertrandite is one mineral that makes up only a few percent of the rock, and pure bertrandite is colorless to pale yellow.
If a listing says "bertrandite" and shows a purple-and-cream nodule, it is Tiffany stone. Naming like this is part of a broader pattern covered in the trade names guide.
How can you recognize Tiffany stone?
Polished, it shows a patchwork of grape to lavender purple fluorite against creamy white, gray-blue and tan silica zones, often with small dark specks. No two nodules match. A few checks help:
- Pattern. The purple is patchy and mottled, not banded in parallel stripes the way agate or rainbow fluorite is.
- Luster contrast. Under a raking light, the fluorite areas look slightly glassier and the opal areas waxier; this is the hard-soft mix at work.
- Weight. With fluorite at 3.18, a Tiffany tumble feels a little heavier than a quartz tumble of the same size.
- Hardness. It will not scratch glass reliably; a steel point can mark the fluorite areas. Test only on an unseen spot, or not at all on a finished piece.
Purple lookalikes include dyed howlite and dyed magnesite, which are evenly colored and often show dye concentrated in cracks, and plain purple fluorite, which lacks the cream opal patches. The fluorite guide and opal guide cover each component on its own.
How durable is Tiffany stone, and how should you care for it?
Geology.com gives Tiffany stone a Mohs hardness of only 5 to 5 1/2 and warns that in a ring it will quickly show wear and lose its polish. It is better suited to pendants, earrings and beads than to rings or bracelets. Fluorite also has perfect cleavage, so a sharp knock can chip an edge.
Care rules follow from the components:
- Wipe with a soft damp cloth; skip vinegar and other acids, which attack the calcite and dolomite.
- Keep it out of ultrasonic and steam cleaners, which can open cleavage cracks in fluorite.
- Store it apart from quartz and agate, which will scratch it.
- Lapidaries who slab or sand it work wet and keep dust down, because the rock carries beryllium and OSHA regulates beryllium as a workplace inhalation hazard. Finished, polished pieces are not a dust source.
What is the price range for Tiffany stone?
Geology.com notes that cabochons with good color, pattern and size can usually be found for $75 or less, and that a sterling silver setting keeps a full piece around $150 or less. Tumbles and small freeforms sell for far less. Price climbs with saturated purple, a crisp contrast between purple and white, a clean polish without undercut soft spots, and size, since large unfractured nodules are uncommon.
What is Tiffany stone associated with in crystal traditions?
In crystal traditions, Tiffany stone is associated with transformation and with combining the qualities attributed to fluorite and opal, which makes sense given that it is literally both. It is often grouped with other purple stones in meditation displays.
Shopping for Tiffany stone and its components
Because Tiffany stone is a by-product of an industrial mine, look for listings that state Utah as the origin, and be wary of any "Tiffany" piece claimed from another country. Judge a piece by color saturation, the ratio of purple to cream, and the quality of the polish across both hard and soft zones.
- Tiffany Stone: Utah material, listed as found, cut and polished by a local rockhound, sold in small and medium/large sizes. A good entry piece to see the mottled purple fluorite and creamy opal side by side.
- Purple Fluorite Clusters on Matrix: a 96 g crystallized fluorite piece from China, about 3 by 1.5 by 1.75 inches. Useful for comparing the same mineral as cubes rather than as a replacement nodule.
- Pink Opal: medium rough chunks of common opal, showing the waxy, non-flashing luster that the opal zones in Tiffany stone share.
- Bingham Fluorite, from Bingham, New Mexico, USA: American fluorite sold by weight bracket, a western-US counterpart for anyone building a small fluorite and Tiffany stone set.
Digital Towns Market
Tiffany stone, fluorite and opal in stock
Frequently asked questions
Is Tiffany stone the same as bertrandite?
No. Bertrandite is a colorless to pale yellow beryllium mineral that occurs as microscopic grains inside the Tiffany stone nodules. The rock is mostly fluorite with opal, chalcedony, quartz and carbonates. "Bertrandite" is a common but inaccurate label for the purple polished material.
Is Tiffany stone still being mined?
The nodules come out with beryllium ore at Spor Mountain, Utah, the only domestic U.S. beryllium source, but the operator crushes nearly all of it for metal. Gem rough reaches the market only in small amounts, mostly from pieces collected over the years.
Is Tiffany stone safe to handle?
Polished pieces are handled routinely and are not a dust source. The concern is dust from cutting or sanding, because the rock contains beryllium. Lapidaries work it wet with dust control. Do not grind, sand or tumble it at home without proper wet methods.
Can Tiffany stone be worn in a ring?
It is not a good ring stone. At Mohs 5 to 5.5, with soft fluorite that cleaves, it scuffs and chips with daily knocks. Pendants, earrings and beads protect it far better and keep the polish looking fresh.
Why is my Tiffany stone polish uneven?
Its components differ in hardness. Fluorite at Mohs 4 wears faster on the polishing wheel than the opal and quartz zones, so the softer purple patches can sit slightly lower. Better-finished pieces minimize this with careful polishing.
Sources
- Geology.com, Tiffany Stone: https://geology.com/gemstones/tiffany-stone/
- USGS National Minerals Information Center, Beryllium Statistics and Information: https://www.usgs.gov/centers/national-minerals-information-center/beryllium-statistics-and-information
- USGS Publications Warehouse, Beryllium, Professional Paper 1802-E: https://pubs.usgs.gov/publication/pp1802E
- Webmineral, Fluorite mineral data: https://webmineral.com/data/Fluorite.shtml
- Webmineral, Bertrandite mineral data: https://webmineral.com/data/Bertrandite.shtml
- OSHA, Beryllium overview: https://www.osha.gov/beryllium