Earth Record
Mineralogy and formation
Variety of Quartz
Before the quartz host fully closed, Before the quartz host fully closed, iron-rich phases had already formed in the cavity. Lepidocrocite, the gamma polymorph of FeO(OH), develops as thin platy crystals under oxidizing, water-rich conditions. Later, silica-saturated fluids deposit quartz around those plates and seal them inside a transparent trigonal host. The resulting stone is composite: quartz provides exterior hardness and optical depth, while the iron oxyhydroxide inclusions generate the red, coppery, or rust-toned interiors.
Mineral dealers often label a wide range of red-included quartz as lepidocrocite quartz, but strict identification can be difficult because hematite, goethite, and other iron minerals also occur in similar settings. Where true lepidocrocite is present, the inclusions tend toward bladed or platy habits rather than needles. Quartz itself stays at Mohs 7, so the finished specimen remains durable despite the softer included phase.
The visual effect comes from suspension. Internal red forms seem to hover within clear silica, held in place by a second mineral generation that arrived later and enclosed them without dissolving them away. In the body, that enclosure feels immediately legible. A vivid, potentially staining material is not expelled. It is contained inside a clearer architecture that lets it remain visible.
The somatic turn follows that image. Regulation does not always erase what is intense or blood-colored. Sometimes it grows a transparent wall around it, making it possible to witness the charge without being cut by direct contact.
Chemical FormulaSiO2 (host: alpha-quartz) + gamma-FeO(OH) (inclusion: lepidocrocite, iron oxyhydroxide)Crystal SystemMixedMohs Hardness7Specific Gravity2.65 (quartz) to 2.70+ depending on inclusion density. Lepidocrocite itself is 3.96-4.09LusterVitreous (quartz exterior). Inclusions display subadamantine to silky luster internally.ColorRed-WhiteIMA Statustrade_nameIMA Numberpre-IMA Brazil's Minas Gerais produces the most lepidocrocite-in-quartz from hydrothermal veins where iron oxyhydroxide formed before or during quartz growth. India yields specimens from Deccan basalt regions. Madagascar produces similar material from pegmatite-associated deposits.
The red-orange lepidocrocite inclusions are sealed inside the quartz and visible through the transparent host at all three sources.
BrazilIndiaMadagascar
Telling it apart
Lepidocrocite in quartz is quartz containing red to reddish brown platy inclusions of lepidocrocite, an iron oxyhydroxide. The market confusion involves hematite inclusions, goethite inclusions, and iron stained quartz all labeled under whichever inclusion name sounds most interesting. Lepidocrocite specifically forms thin platy to micaceous crystals within the quartz host, often appearing as reddish fire like patches or scattered red flakes.
Hematite inclusions tend to be more metallic and specular. Goethite inclusions often appear as needles or fibrous bundles in brown to yellow. The quartz host tests normally at Mohs 7 with no cleavage. If the red inclusions are platy and distributed as internal fire like patches, lepidocrocite is a reasonable identification. If they are metallic or needle like, a different iron mineral is more likely.
Spotting the real thing
Lepidocrocite in quartz: red-orange inclusions should be INSIDE the quartz host (Mohs 7). The inclusions are iron oxyhydroxide flakes or plates sealed during quartz growth. If the red-orange is only on the surface, it is surface staining, not genuine lepidocrocite inclusion.
The inclusions should show metallic to subadamantine luster internally.
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