Jasper, specifically “picture”

Jasper is an opaque variety of microcrystalline quartz (chalcedony + moganite) colored by impurities. We add the word picture when the patterns resemble natural scenes—horizon lines, shorelines, dunes, or tree silhouettes created by mineral staining and layered deposition.

An umbrella, not a single mine

“Picture jasper” is a descriptive umbrella used for scenic jaspers from multiple localities. In the Pacific Northwest, names like Owyhee, Biggs, Deschutes, Bruneau, and Morrisonite each carry their own look and geology. Similar scenic jaspers occur worldwide.

Layering & quiet water

Many picture jaspers began as silicified siltstones, mudstones, or ash‑rich sediments. Calm deposition produces thin beds; gentle shifts in sediment size and chemistry draw parallel bands that our brains read as horizons.

Oxide staining

Groundwater carrying iron and manganese migrates through pores and micro‑cracks. Oxides precipitate along certain planes, drawing lines, tree‑like dendrites, and cloud‑like washes. Iron tends red/yellow; manganese tends black/brown.

Silica “glue”

Silica (from volcanic ash or circulating fluids) percolates through the sediment, replacing and cementing it into chalcedony. The resulting stone is tough, takes a high polish, and locks the “painting” in place.

Cross‑beds & angles

Ancient dunes and ripple marks can produce angled laminae (cross‑bedding) that mimic hillsides, bluffs, or seashores. Where beds truncate, you get natural “cliffs” and “canyons.”

Soft faults & seams

Minor fractures filled by iron oxides draw tree‑trunk lines or “fences.” Later silica may heal them—your eye sees a dark trunk with a pale sky behind it.

Why scenes look so… scene‑like

Our brains are tuned to horizon + sky + foreground. Picture jasper’s parallel color blocks and occasional vertical strokes hit that formula perfectly—instant landscape.

Palette

• Sand & cream — silica‑rich beds, clay‑light layers.
• Camel & tan — iron‑warmed sediments.
• Umber & mocha — heavier iron/manganese zones.
• Blue‑grey “sky” — fine clay/silica bands or chalcedony halos.
• Brick/red — hematite‑rich lines and panels.
• Ink black — manganese dendrites and veinlets.

Some varieties lean pastel (Owyhee), others bold and high‑contrast (Biggs, Deschutes). A few display greenish tints from mixed Fe states or chloritic impurities.

Pattern vocabulary

• Horizon banding — long, parallel layers suggesting ground and sky.
• Cloud banks — diffuse, lighter washes near the “sky” band.
• Buttes & mesas — rectangular blocks from truncated beds.
• Tree lines — dendritic manganese “branches” along micro‑cracks.
• Shorelines — gently curved contacts with a pale “water” strip.
• Paneling — calm, wide color fields with just a few bold strokes.

Photo tip: Side‑light at ~30° reveals subtle relief along bed contacts; a white bounce card opposite the light keeps creams bright and reds true.

Micro‑mosaic

At 10×, the groundmass is a tight micro‑quartz mosaic. Where beds change, grain size/impurity shifts subtly—your “horizon” boundary.

Dendrites vs. veins

Dendrites look like fern twigs radiating from a centerline (manganese along a crack). Veins are straighter, often agate‑filled. Both can appear in one scene.

Healed stories

Look for hairline chalcedony heals crossing beds. They can catch light and read as “waterlines” under raking illumination—geology’s own highlight pen.

“Painting stones” (dendritic limestone/marble)

Very scenic, but carbonate. Quick tells: acid fizz on an inconspicuous chip; softer feel; pearly cleavage flashes. Picture jasper (quartz) won’t fizz and scratches glass.

Polychrome/Desert/Mookaite jaspers

Earthy color blocks without the strong horizon + sky motif. Micro‑textures may differ (more breccia mosaics, fewer dendrites).

Leopard “jasper” (orbicular rhyolite)

Orbicular spots and devitrified rhyolite groundmass; lacks the long, scenic bands and dendritic “trees.”

Dyed composites

Neon or uniform color fields with repeating motifs are suspicious. Natural picture jasper shows gentle, organic variation and non‑repeating scenes.

Quick checklist

• Quartz‑hard; no fizz; takes a glassy polish.
• Parallel bands suggest horizons; black dendrites may “grow” like trees.
• Scenes vary naturally—no copy‑paste clouds.

At‑home observations

Use a loupe: dendrites are fractal, branching; inked lines are oxide films; agate heals are translucent. Together they make the landscape convincing.

Pacific Northwest, USA

• Owyhee (Oregon/Idaho) — soft blue‑grey “skies,” cream sands, calm horizons.
• Biggs (Oregon) — bold chocolate‑to‑caramel panels with dark lines and “buttes.”
• Deschutes (Oregon) — high contrast, crisp horizons; classic “canyon” scenes.
• Bruneau (Idaho) — layered tans and reds with sweeping curves.
• Morrisonite (Oregon) — often called the “king of jaspers”; complex scenes, rich tones, agate heals.

Elsewhere

Scenic jaspers also occur in Australia (e.g., Noreena’s blocky panels), Africa, Mexico, and Madagascar. Trade names vary; the common thread is a landscape‑like arrangement of bands and stains.

Everyday care

• Quartz‑hard = good durability; still protect edges from sharp impacts.
• Clean with lukewarm water + mild soap; soft cloth/brush; rinse and dry.
• Avoid harsh acids/bleach—unnecessary and may haze polish.

Display

• Orient slabs so the horizon sits level—your “landscape” reads instantly.
• Side‑light around 30° to make dendrites and bed contacts pop.
• Felt pads under bases; larger pieces are hefty.

Lapidary

• Pre‑polish patiently to keep horizon lines crisp.
• Domes look best when the “scene” traverses the apex; avoid placing a fracture right at the skyline.
• Finishes: diamond through 3k–8k → cerium/oxide on soft pad; light pressure to avoid undercutting softer oxide films.

Find the horizon

Hold the slab at arm’s length and tilt slowly. Where do the longest, calmest bands line up? That’s your natural horizon—now the scene snaps into focus.

Tree or crack?

Under a loupe, follow a “tree.” If it branches repeatedly into finer twigs, it’s a manganese dendrite. If it stays straight and uniform, it’s a healed crack doing a very good impersonation.