Red Jasper Identification Guide

What Red Jasper Looks Like

Red jasper is an opaque microcrystalline quartz (chalcedony group) heavily colored by iron oxide (hematite) inclusions, giving a uniform brick- to brownish-red. Unlike agate and carnelian, it transmits essentially no light.

• Color: brick-red to deep brownish-red, sometimes with darker veining or yellow patches
• Luster: dull to waxy; vitreous when highly polished
• Transparency: opaque
• Habit: massive, fine-grained; no crystals visible; nodules and veins

Step-by-Step Field ID Checklist

1. Backlight it — red jasper stays opaque; no glow through thin edges (vs translucent agate/carnelian).
2. Check color uniformity — a solid, dusty red, sometimes mottled.
3. Test hardness against glass and steel.
4. Look at the break — smooth conchoidal fracture with a waxy sheen.
5. Scratch a streak plate — jasper leaves a pale streak (the iron is locked in silica), unlike pure hematite.

Key Diagnostic Tests

• Mohs hardness: 7 — scratches glass and steel easily.
• Fracture: conchoidal; no cleavage.
• Streak: white to pale yellowish (not red — important vs hematite).
• Specific gravity: ~2.6.
• Acid: no reaction.
• Opacity: consistently opaque, a defining trait of jasper.

Common Look-Alikes and How to Tell Them Apart

• Carnelian: same mineral family but translucent and evenly orange-red; carnelian glows when backlit, jasper does not.
• Red agate: translucent and banded; jasper is opaque and unbanded.
• Hematite: much heavier (SG ~5.3), metallic to dull luster, and leaves a red-brown streak; jasper leaves a pale streak.
• Red chert/flint: very similar, but jasper is typically more vividly and uniformly red; chert tends toward duller grays and browns.
• Brecciated jasper: angular fragments cemented together — still jasper, just a textural variety.

Where It Is Found

Red jasper occurs worldwide wherever iron-rich silica precipitated — major sources include India, Russia, the USA, Australia, and Brazil, in sedimentary and hydrothermal settings.

Collector's Notes and Common Mistakes

The single best test for red jasper is opacity — backlight any thin edge, and if no light passes, you have jasper rather than translucent carnelian or banded agate. The second confusion is with hematite: although both are iron-colored and reddish, hematite is far denser (SG ~5.3), often shows a metallic sheen, and leaves a red-brown streak, whereas jasper is light (SG ~2.6) and leaves a pale streak because its iron is locked inside silica. Note that the line between red jasper, chert, and flint is gradational and partly regional; vivid, uniform red usually earns the "jasper" label. Some inexpensive "red jasper" beads are actually dyed or reconstituted material — look for color in drill holes and an unnaturally even tone. Jasper is tough (hardness 7, no cleavage) and takes an excellent polish, making it a favorite for cabs, beads, and carvings. For rough, scan iron-rich sedimentary outcrops, riverbeds, and old mine dumps for dense, dull-red massive chunks.