Boleite
Boleite is halides (complex Pb-Cu-Ag chloride), KPb26Ag9Cu24Cl62(OH)48. In the hand, it rates 3 to 3.5 on the Mohs scale, and it runs deep indigo blue and prussian blue. Deep indigo, seemingly perfect little cubes with a blue streak and surprising heft, classic specimens come loose like dice from Baja clay.
The geology.
Boleite carries the formula KPb26Ag9Cu24Cl62(OH)48. It belongs to the tetragonal (pseudo-cubic) system. Its listing category is halides (complex Pb-Cu-Ag chloride).
It sits at 3 to 3.5 on the Mohs scale. The surface reads vitreous to pearly. Light behaviour is translucent to nearly opaque. Specific gravity runs 5.05. The streak is blue, slightly greenish. It breaks with perfect cleavage; uneven fracture.
Deep indigo, seemingly perfect little cubes with a blue streak and surprising heft, classic specimens come loose like dice from Baja clay.
It turns up mostly as sharp cube-like crystals, crystals in matrix or thumbnail specimens.
The origins.
Boleo copper district, Santa Rosalia, Baja California Sur, Mexico; minor occurrences in Chile and Australia.
On value, the database notes: collector mineral; sharp Boleo cubes command three-figure-plus prices.
Traditional associations.
In energy work traditions, associated with deep insight and communication across distance.
This is lore, and we label it as lore. The measurable facts are further up the page.
Spotting the real thing.
Deep indigo, seemingly perfect little cubes with a blue streak and surprising heft, classic specimens come loose like dice from Baja clay.
Rarely faked due to obscurity; beware dyed halite or fluorite cubes offered to beginners as boleite.
| Looks like | How to tell them apart |
|---|---|
| Fluorite cube | Fluorite is glassier, lighter (SG 3.2), streaks white, and shows octahedral cleavage flashes |
| Galena cube | Galena is metallic silver-gray with gray-black streak |
| Azurite crystal | Azurite forms bladed or tabular monoclinic crystals, never neat cubes |
At-home tests.
A loupe and a window seat settle most questions about boleite. No workshop required.
| Test | What you should see |
|---|---|
| By eye | Blue streak on unglazed porcelain is highly distinctive |
| By eye | Very heavy for size (SG over 5) |
| Scratch check | Soft, a copper coin scratches it |
Destructive tests belong to a gemologist, not a kitchen table. If a piece matters to you, pay for an appraisal before you take a file to it.
Care & handling.
At 3 to 3.5 on the Mohs scale this is a soft material. Keep it as a display piece, store it apart from harder stones, and skip daily-wear settings.
It breaks with perfect cleavage; uneven fracture, which is worth knowing before you set it or drop it.
Clean it by hand, dry it properly, and keep it away from ultrasonic cleaners and hot steam.
Contains lead and copper chlorides: wash hands after handling and never use in elixirs.
A deeper look.
Extended detail on composition, sourcing, authentication and market value.
The physical record
The formula on record is KPb26Ag9Cu24Cl62(OH)48. Crystal system: Tetragonal (pseudo-cubic). Specific gravity: 5.05. Streak: Blue, slightly greenish. Cleavage and fracture: Perfect cleavage; uneven fracture.
How it reaches the market
Boleo copper district, Santa Rosalia, Baja California Sur, Mexico; minor occurrences in Chile and Australia.
What it gets confused with
Fluorite cube: Fluorite is glassier, lighter (SG 3.2), streaks white, and shows octahedral cleavage flashes. Galena cube: Galena is metallic silver-gray with gray-black streak. Azurite crystal: Azurite forms bladed or tabular monoclinic crystals, never neat cubes.
What it is worth
Collector mineral; sharp Boleo cubes command three-figure-plus prices.
Where buyers get caught
Rarely faked due to obscurity; beware dyed halite or fluorite cubes offered to beginners as boleite.
One more thing
Boleite cubes are actually three interpenetrating tetragonal crystals imitating a cube, a disguise so good it fooled early crystallographers.
An education-first guide.
We do not stock boleite. Writing it up regardless is the point of a reference library.
Explore the Crystal Guide