| name | gold-washing |
| description | Alluvial gold recovery using panning, sluicing, and classification. Covers site reading (geological indicators, stream dynamics, pay streak location), panning technique, sluice box operation, and responsible extraction practices. Use when prospecting in an area with known or suspected alluvial gold deposits, sampling a stream to test for gold presence, maximizing recovery during recreational panning, or assessing a site's gold potential before investing more effort.
|
| license | MIT |
| allowed-tools | Read |
| metadata | {"author":"Philipp Thoss","version":"1.0","domain":"prospecting","complexity":"intermediate","language":"natural","tags":"prospecting, gold, panning, sluicing, alluvial, placer, geology"} |
Gold Washing
Recover alluvial gold from stream deposits using panning, sluicing, and classification techniques.
When to Use
- You are prospecting in an area with known or suspected alluvial gold deposits
- You want to sample a stream or river to test for gold presence
- You are recreational panning and want to maximize recovery
- You need to assess a site's gold potential before investing more effort
Inputs
- Required: A gold pan (14-16 inch, with riffles)
- Required: Access to a stream, river, or alluvial deposit
- Optional: Classifier/screen (1/4 inch mesh)
- Optional: Sluice box (for higher volume processing)
- Optional: Snuffer bottle or tweezers (for fine gold recovery)
- Optional: Vial with water (for storing recovered gold)
- Optional: Shovel and bucket for material collection
Procedure
Step 1: Read the Site
Gold is heavy (specific gravity 19.3) and concentrates predictably. Read the water and geology before digging.
Where Gold Concentrates:
INSIDE BENDS:
Water slows on inside curves of a stream. Heavy materials
(including gold) drop out of suspension here. Sample the
gravel bar on the inside of bends.
BEHIND OBSTRUCTIONS:
Large rocks, fallen trees, and bedrock ledges create
low-pressure zones behind them. Gold settles in these
"shadow" areas.
BEDROCK CRACKS:
Gold works its way into cracks and crevices in bedrock.
Cleaning out bedrock cracks (crevicing) can be very productive.
PAYSTREAKS:
The heaviest concentration follows a line (paystreak) along
the inside of the bend, continuing from one inside bend to the
next. Experienced prospectors trace this line.
WHERE TO SAMPLE:
+--------------------+------------------------------------------+
| Feature | Sample Location |
+--------------------+------------------------------------------+
| Inside bend | 1-2 feet above waterline in gravel bar |
| Behind boulder | Downstream side, in the calm pocket |
| Bedrock exposure | In cracks and depressions |
| Stream confluence | Where tributary meets main stream |
| Old flood channels | Elevated terraces above current stream |
+--------------------+------------------------------------------+
Geological Indicators:
- Black sand (magnetite/hematite): gold's travel companion.
Where black sand concentrates, check for gold.
- Quartz veins in surrounding rock: gold often forms in
quartz veins; erosion releases it into streams
- Iron staining (rust-colored rock): indicates oxidation zone,
which can host gold deposits
Expected: You have identified 2-3 promising sample locations based on stream dynamics and geological indicators.
On failure: If no clear indicators are visible, sample multiple locations systematically — one pan from each distinct feature (inside bend, behind obstacle, random gravel bar). Even a single color (flake of gold) confirms the stream carries gold.
Step 2: Classify and Collect Material
Prepare the raw material for panning.
Collection Protocol:
1. Fill a bucket from your chosen sample location
2. Dig to bedrock if possible — gold concentrates on or near bedrock
3. If bedrock is deep, sample the bottom 6-12 inches of gravel
(gold migrates downward through gravel over time)
Classification:
1. Place a 1/4 inch classifier over your gold pan or bucket
2. Shovel material onto the classifier
3. Shake and wash through — fine material drops into the pan,
large rocks and gravel remain on top
4. Inspect oversized material briefly (nuggets can be caught
by the classifier) then discard
5. Classified material is now ready for panning
Expected: A pan or bucket of classified material (gravel and sand smaller than 1/4 inch), sourced from a geologically promising location.
On failure: If you cannot reach bedrock, sample what is accessible. Shallow samples are less likely to contain gold but are still worth testing — flood events can deposit gold at various depths.
Step 3: Pan the Material
The gold pan separates gold from lighter material using gravity and water.
Panning Technique:
INITIAL WASH:
1. Submerge the pan in water (stream, bucket, or tub)
2. Break up any clay or cemented material with your fingers
3. Remove large stones by hand (inspect each for attached gold)
STRATIFICATION:
4. Shake the pan vigorously side to side (NOT circular) while
submerged — this settles heavy material to the bottom
5. Tilt the pan slightly and allow lighter material to wash off
the front lip
6. Shake, tilt, wash. Shake, tilt, wash. Repeat.
FINE PANNING:
7. As material reduces, you should see black sand concentrating
8. Reduce water flow — gentle swirling now, not vigorous shaking
9. Tilt the pan at a shallow angle and let a thin sheet of water
wash across the concentrate
10. Gold (bright yellow, stays at the bottom) separates from
black sand (dark, slightly lighter)
RECOVERY:
11. Use a snuffer bottle to suck up individual flakes/pieces
12. Or carefully pour off water and collect the concentrate
13. Transfer gold to a vial with water for storage
Common Errors:
- Circular motion washes gold OVER the riffles and out of the pan.
Use side-to-side shaking for stratification.
- Too aggressive: panning too fast loses fine gold. Be patient.
- Not enough initial shaking: gold must sink to the bottom before
you start washing off material.
Expected: All heavy material (gold, black sand, garnets) concentrates in the bottom of the pan. Gold is visible as bright yellow flakes, flattened grains, or (rarely) small nuggets.
On failure: If no gold is visible after a careful pan, the location may not contain gold — or the gold may be too fine to see (flour gold). Check with a hand lens. If still nothing, move to a different sample location.
Step 4: Scale Up with a Sluice Box (Optional)
For processing larger volumes of material.
Sluice Box Operation:
1. Set the sluice in running water at a slight angle (about
1 inch of drop per foot of length)
2. Water should flow smoothly over the riffles — enough to move
sand but not enough to flush the riffles clean
3. Feed classified material into the top of the sluice gradually
4. Let the sluice work — gold is trapped behind the riffles,
lighter material washes through
5. Clean the sluice every 20-30 minutes:
- Remove the sluice from the water carefully
- Wash the riffle mat into a bucket or gold pan
- Pan the concentrate to recover gold
Sluice Calibration:
- Too much water: gold bounces over riffles and is lost
- Too little water: material builds up and buries the gold
- Test with a lead split shot: drop it in the top of the sluice.
If it is caught by the riffles, gold will be too.
Expected: Higher volume processing with gold concentrated in the riffle mat, recovered by final panning.
On failure: If the sluice is not catching test material (lead shot), adjust the angle or water flow. The sluice should catch everything heavier than quartz sand.
Validation
Common Pitfalls
- Panning too fast: Impatience loses fine gold. A proper pan takes 5-10 minutes. Speed is the enemy of recovery
- Ignoring black sand: If you see heavy black sand concentrating, gold is likely present — even if too fine to see without magnification
- Confusing pyrite with gold: Pyrite (fool's gold) is lighter, breaks when pressed with a pin, and has a brassy rather than buttery yellow colour. Real gold is malleable and does not tarnish
- Sampling random locations: Gold concentrates predictably. Sampling the middle of a straight stretch is far less productive than sampling the inside of a bend
- Environmental damage: Respect waterways. Do not dig large holes in stream banks, do not use mercury (illegal in most jurisdictions and extremely toxic), and fill in any test holes
- Ignoring regulations: Most jurisdictions require permits for gold prospecting, even recreational panning. Check local regulations before starting
Related Skills
mineral-identification — understanding rock and mineral types helps read geological indicators that point to gold-bearing areas
