You might have heard people talk about colloidal silver, but what does that really mean? Let’s break it down in a way that’s easy to understand.

What Is a Colloid?

A colloid is a mix of tiny bits of something (called particles) that float around in another substance. These particles are so small that you can’t see them with your eyes—or even with most microscopes! But they’re still bigger than individual atoms or molecules.

Think of fog: it looks like a cloud in the air because it’s made of tiny water droplets floating around. That’s a colloid.

• Particles in a colloid are really small—about 1 to 1,000 nanometers across. (A human hair is about 76,000 nanometers wide!)
• They don’t settle to the bottom like sand in water.
• They can scatter light. This is why you can see car headlights in fog. This is called the Tyndall effect.

What Is Colloidal Silver?

Now that you know what a colloid is, let’s talk about colloidal silver.

Colloidal silver is:

• Tiny bits of pure silver metal floating in water.
• These bits are so small that they stay mixed in the water and don’t sink.
• There are also usually some silver ions, which are single atoms of silver with an electric charge.

It’s important to know that real colloidal silver must have tiny silver particles in it—not just silver ions. If it’s only ions, it’s not a colloid. And if the silver bits are too big and sink to the bottom, it’s not a colloid either—it’s a suspension.

What’s the Difference?

Here’s a simple chart to show the difference between three types of mixtures:

Type	Particle Size	What Happens
Solution	Too small to see	Stays mixed, like salt water
Colloid	Very tiny but larger	Stays mixed and scatters light
Suspension	Big particles	Sinks to the bottom, like muddy water

So, colloidal silver sits in the middle. It’s not too small (like a solution) and not too big (like a suspension). It’s just right, with tiny bits of silver floating in water.

Why Does This Matter?

It’s easy to get confused. Some products say they’re “colloidal silver,” but they might only have silver ions and no particles. That’s not true colloidal silver.

Size matters: Others might have silver clumps that are too big, which means they could settle out and not work the same way.

Knowing the difference helps people understand what they’re using—and make sure they’re getting what they think they are.

Home Testing of Colloidal Silver

There are a few simple at-home tests that can help you determine what kind of colloidal silver you have—whether it’s mostly ionic, truly colloidal (with particles), or a suspension. While not perfect, these tests can give you useful clues:

1. The Tyndall Effect Test (Light Beam Test)

Purpose: Detects suspended particles (a hallmark of true colloids).

How to do it:

In a dark room, shine a laser pointer or small flashlight through your colloidal silver in a clear glass.

Look from the side to see if the beam is visible in the liquid.

What it tells you:

If you can see the beam clearly (like a line of light), this means there are particles scattering the light—a sign of colloidal silver.

If the beam isn’t visible, it might be mostly ionic silver or too low in particle content to qualify as a colloid.

2. Freezer Test (Particle Stability Check)

Purpose: Checks if particles are stable or if they clump together.

How to do it:

Put a sample of your colloidal silver in a small clear jar or glass.

Freeze it overnight.

Let it thaw slowly at room temperature.

What it tells you:

If it turns cloudy or forms flakes, your colloid has large particles or is unstable—possibly a suspension, not a true colloid.

If it remains clear, it likely contains very small and stable particles (or mostly ions).

3. Salt Test (Ionic Silver Reaction)

Purpose: Checks for the presence of silver ions.

How to do it:

Add a few drops of table salt water (dissolve salt in distilled water) to your silver solution.

What it tells you:

If it turns cloudy or forms white flakes, that indicates silver ions reacting with chloride in the salt to form silver chloride.

No cloudiness suggests fewer ions—possibly more of a true colloid.

Note: This test only shows the presence of ions, not particle size or purity.

4. Color Observation

What to look for:

Clear or light yellow color usually means ionic silver.

Amber, golden, or grayish tint often means particles are present.

Dark brown, murky, or black may mean particles are too large—a suspension or degraded product.

5. Conductivity Test (Optional, for DIY scientists)

If you have a TDS (total dissolved solids) or conductivity meter, you can:

Test the electrical conductivity.

Higher conductivity usually means more ions, not particles.

True colloidal silver with only particles and few ions often shows very low conductivity.

Summary Table

• A colloid is a mix with tiny particles that don’t settle out.
• Colloidal silver has tiny silver particles floating in water.
• It also often has silver ions, but particles are what make it a colloid.
• Watch out for products that use the term “colloidal” incorrectly!

Home Testing References and Where to Learn More

Sources

• Schramm, L.L. Colloids and Interfaces in Oil and Gas Industries, 2001.
• Gibbs, W.F. The Truth About Colloidal Silver, 1990.
• Key, M. Colloidal Silver Today, 2000.
• Encyclopædia Britannica, “Colloid” entry.
• Silver Institute and PubMed research on particle size and light scattering.