Vermiculite insulation in this attic ceiling may contain asbestos fibers. Vermiculite Insulation Identification
How to recognize vermiculite insulation; Vermiculite identification photos

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Vermiculite insulation identification.

How to identify vermiculite or vermiculite insulation by visual inspection. It's easy, as we'll show you here.

This article series explains how to recognize vermiculite building insulation that may contain asbestos fibers. This article permits visual identification of vermiculite insulation; we include our own as well as US EPA photographs of various forms of vermiculite insulation to assist in recognizing vermiculite in buildings. We describe the history of vermiculite insulation, the asbestos hazard that may be present depending on which vermiculite insulation product is present, and how asbestos is identified in vermiculite insulation.

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How to Identify Vermiculite Insulation - Photographs, Description, Properties

Vermiculite Insulation particles (C) Daniel Friedman

Watch out: vermiculite from some sources contains asbestos and can be an asbestos dust hazard in buildings. Details about the asbestos content in some vermiculite insulation products is found in this article.

Article Contents

Watch out: while it is certainly possible to identify a material as vermiculite or vermiculite insulation by examining it with the naked eye or by examining photographs such as those on this page, one cannot determine whether or not vermiculite contains asbestos simply by looking at it with the naked eye nor by comparing photographs of the insulating material.

[Click to enlarge any image]

To absolutely identify asbestos content in vermiculite microscopic examination using polarized light (PLM) is necessary.
See ASBESTOS TESTING LAB LIST if you need to have an insulation sample tested for asbestos.

Vermiculite Insulation Identification Photographs

We have observed that depending on the mine from which it originates, and the process used to expand the vermiculite particles, vermiculite may vary in appearance and shininess.

Vermiculite insulation is easy to identify by visual inspection, as it is a granular, loose-fill pour-in insulation comprised of particles typically gray or brown or silver-gold in color, often with bits of reflective mica included.

What can be confusing is that vermiculite particle sizes range from about 1/8" in diameter to more than 1/2" in diameter depending on the producer and batch, with a few large particles that can be more than one inch in length.

The individual vermiculite insulation particles, an expanded mineral, are quite light in weight. Depending on the condition of the vermiculite insulation, whether or not it has been disturbed, and also depending on its original manufacture and quality, various amounts of dust and ultra-small particles may also be present.

Vermiculite insulation may be comprised of particles of several colors and shades (see our page top photo), or nearly all of the particles may be consistently the same color, as we show in our close up photograph of vermiculite (left). This photo shows how we noticed the presence of vermiculite insulation by peering through a crack between attic floorboards. It was not necessary to remove flooring to find this material.

Vermiculite insulation in this attic ceiling may contain asbestos fibers.

Our first two vermiculite attic insulation photos (above and just below) show what you may see in the typical attic of an older home where vermiculite was added to the attic floor. You will often find a mix of several kinds of building insulation, and the vermiculite may, for example, have been covered-over by rolled out fiberglass or fiberglass batt insulation.

Vermiculite insulation in this attic ceiling may contain asbestos fibers.

Below we illustrate that in "original" condition, that is without mechanical damage from being walked-on, vermiculite insulation products can vary considerably in size and appearance.

Vermiculite insulation small particles (C) Daniel Friedman

The two vermiculite photos above and the third further below illustrate a considerable range in average particle size in different vermiculite insulation products, possibly coming from different mines or from different expansion processes.

Vermiculite insulation medium particles (C) Daniel Friedman

For reference, the very large vermiculite particle at below left was 1.5 cm x 1 cm in size, and some reports indicate that pour-in attic insulation can contain vermiculite particles up to an inch (2.5 cm) in length. As you can see in our vermiculite insulation images here, the color of the material ranges from a creamy white to gold or tan in color.

Vermiculite insulation large 1.5cm particles (C) Daniel Friedman

Just below, in the same largest-particle-size vermiculite sample, you can observe the mica-like shiny surface and layering or laminate structure of some of these vermiculite particles.

Vermiculite insulation mica like flakes (C) Daniel Friedman

Watch out: vermiculite insulation was not only poured into attic floors but also into building wall cavities during insulation retrofit projects. Particularly in older balloon-framed buildings, vermiculite could be poured from the attic right into wall cavities extending all the way to the building foundation top. Vermiculite was also often poured into hollow-core concrete block walls.

Unidentified Vermiculite Insulation Photographs

Mississippi home inspector Dan Phillips sent along these interesting photographs of vermiculite insulation from a 1940's home in Tennessee.

Vermiculite in a 1940s Tennessee home (C) D Friedman D Phillips

Phillips added "The home itself was built in the 40’s and had several renovations done to it. The vermiculite was added during one of these renovations in the past, and covered some older insulation as well as serving as single insulation to newer portions of the home." He observed that this particular vermiculite insulation was comprised of a mix of both small reflective mineral fragments (mica-like) as well as larger fragments up to almost 1/4" of expanded vermiculite insulation material.

Vermiculite in a 1940s Tennessee home (C) D Friedman D Phillips

Without testing by a certified asbestos testing laboratory, we don't know if this particular vermiculite contains asbestos or not, - appropriate warnings were issued to the client. That experience reminds us that in an older home there are often multiple kinds of insulation present, and they may not all be visible, newer materials having covered older.

Question: what is the origin of Westroc Vermiculite

2016/03/21 Anonymous said:
Where did Westroc get its vermiculite from


Anonymous, I'm not able to give a comprehensive answer because Westroc branded vermiculite could have originated at more than one location. However, research I cite below indicates the Westroc [vermiculite] mine located in British Columbia (Canada).

Question: Where did Gold Nugget insulation come from

2016/03/22 murrayhillson said:

Where did gold nugget insulation come from?

Reply: "gold nugget" or "silver nugget' vermiculite terminology

Vermiculite insulation large 1.5cm particles (C) Daniel Friedman


Assumng you are asking about gold nugget vermiculite insulation, the term "gold nugget" is very widely in literature describing some nugget-like forms of vermiculite used as building insulation as well as in other applications. I did not find instances of specific "gold nugget vermiculite" as a vermiculite product brand name. If you have such literature, photographs, etc. use our page bottom CONTACT link to send me that information and those photos or images and I'll research further.

If you are representing a law firm or are involved in litigation, please so identify yourself.

These questions, probably both from Murray, were posted originally at MUNN & STEELE VERMICULITE, MICA-FIL, Siscoe Vermiculite Mine

Vermiculite Insulation Identification Images from the US EPA & Other Sources

Table of Vermiculite Insulation Types & Identification Photos

Typical vermiculite insulation

Vermiculite insulation between attic joists

Typical vermiculite insulation

Vermiculite insulation particle size

Different sizes of vermiculite particles;

Chinese vermiculite from the Leijie Trade Co., Ltd.

White / Golden Vermiculite, Chinese: Leijie Trade Co.


EPA Images retrieved 08/17/2010, original source:

Chinese white vermiculite, retrieved 03/25/2015, original source: Leijie Trade Co., Ltd., Shijiazhuang City, Hebei Province Xinhua China, Website, Excerpt from the Leijie Trade company's description of their vermiculite product:

Vermiculite is a member of the phyllosilicate group of minerals, resembling mica in appearance. It is found in various parts of the world, vermiculite is basically a hydrated phlogopite mica which has the remarkable ability to expand to many times than its original volume when heated at 850 °C.Vermiculite is most widely used in its exfoliated form. The concertina-shaped granules of exfoliated vermiculite are non-combustible as well as being insoluble in water and all organic solvents.

Chinese vermiculite and perlite is provided by Hebei Leijie Mineral Co., Ltd. in both raw ore and expanded form in the following sizes:

  • Raw Ore Perlite : 10-20 mesh , 20-40 mesh ect
  • Expanded Perlite : 1-3mm , 2-4mm, 3-6mm ect
  • Raw Ore Vermiculite : 0.3-1mm , 1-2mm , 2-4mm ect
  • Expanded Vermiculite : 1-3mm , 2-4mm , 3-8mm ect.

General Chemical Composition of Vermiculite

The Leijie company includes tables of the chemical composition of vermiculite that varies depending on the vermiculite's general color. Basic chemical components of vermiculite, varying by percentage according to where the material was mined and its color, include SiO2, Al2O3, MgO, Fe2O3, FeO, TiO2, at a pH varying between 7-10. Expanded vermiculite particle sizes range from 1mm. upwards as described above.

Vermiculite Loose Fill Attic Insulation May Go Unrecognized as a Potential Hazard

Home inspector David Grudzinski provides the following vermiculite insulation photographs. Mr. Grudzinski comments:

I write this ... because of the irony in the situation. .... I found some traces of vermiculite in the basement at first in what looked like an area that one would use as a potting shed spot, so I was alert, but not alarmed. I explained what I found to the buyer and his father, and explained that I would be on the look out for other signs of vermiculite in the house.

The attic revealed what I was afraid of. Bags and Bags of the stuff [vermiculite loose fill building insulation produced by W.R. Grace & Co.]. Now I calmly explained the history and concerns to the buyer, then we began to look around and take photos.

Vermiculite insulatin bags in an attic (C) D Friedman D Grudzinski

What struck me as ironic was that when I started to look deeper, the past occupant must have been in a boiler school program of some kind. there were book about boilers laying on the bags. but then after looking farther, there are actually books about asbestos containment and control sitting right on the bags of Zonolite™ insulation. In the ["Guidance for Controlling Asbestos Materials in buildings" U.S. EPA] book found on the attic floor [right next to this vermiculite insulation] was a picture of the standard corrugated asbestos pipe wrapping you see on a furnace - but this was too funny.

Vermiculite insulatin bags in an attic (C) D Friedman D Grudzinski

Article Series Contents


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