About this stone
Color
YellowGoldBrownReddish-Brown (as inclusions in quartz/amethyst)
Origin
BrazilUSACzech RepublicMadagascar
Mohs hardness
3–4 (cacoxenite itself); 7 (host quartz)
Treatment categories
Natural
Industry-standard treatment
Untreated. Cacoxenite in the bead trade is almost always a host quartz (clear or amethyst) containing radiating cacoxenite fibers — the durability comes from the quartz matrix.
Mineral chemistry
Iron aluminum phosphate hydroxide hydrate — Fe24Al(PO4)17O6(OH)12·17H2O
Crystal system
Hexagonal
Stone family
Phosphate (inclusion in quartz host)
Common cuts
RoundFaceted RoundRondelleCoin
Common sizes
6mm8mm10mm12mm
Care notes
Inclusion-bearing quartz is durable (host Mohs 7); mild soap and soft cloth. Avoid ultrasonic on heavily included specimens where internal fractures may have formed around the inclusions.
Related stones
Amethyst, Crystal Quartz, Rutilated Quartz, Tourmalinated Quartz
Frequently asked questions
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What is cacoxenite in the bead trade?
In beads, 'cacoxenite' almost always refers to a host quartz — clear quartz or amethyst — containing radiating fibrous inclusions of cacoxenite, an iron aluminum phosphate. Cacoxenite itself is soft (Mohs 3–4) and not durable enough to be cut as a standalone bead, so the workable material is the quartz matrix (Mohs 7) carrying the golden-to-reddish-brown inclusions. -
How durable are cacoxenite beads for daily wear?
Durability comes from the host quartz at Mohs 7, which handles bracelets, necklaces, and earrings well. Clean with mild soap and a soft cloth. Avoid ultrasonic and steam cleaners on heavily included pieces, since internal fractures can form around inclusion clusters. -
What's the difference between cacoxenite, rutilated quartz, and tourmalinated quartz?
All three are quartz with mineral inclusions, but the included mineral differs. Cacoxenite shows soft yellow-to-reddish-brown radiating tufts or starbursts of phosphate fibers. Rutilated quartz contains straight, often metallic gold or copper rutile needles. Tourmalinated quartz hosts black schorl tourmaline needles. Cacoxenite is also frequently found within amethyst, which the other two typically are not. -
Are cacoxenite beads treated or dyed?
The trade standard for cacoxenite-in-quartz is natural and untreated — the coloration comes from the inclusions themselves. Amethyst hosts may have been heat-treated as part of standard amethyst processing in some material. Treatment disclosure varies by supplier and lot, so ask before buying if not specified. -
What sizes and cuts of cacoxenite does Dakota stock?
Current stock centers on 6mm and 8mm, with 4mm, 7mm, 10mm, and larger graduated and freeform sizes also represented. Cuts in the collection include smooth rounds, rondelles, faceted rounds, faceted rondelles, tri cut rondelles, hexagons, prisms, and energy prisms. Active stock shifts — check the grid for what's drilled and available now.