Seth Roffman

In response to the destructive pumice strip mining taking place in Northern New Mexico’s Jemez Mountains, eco-preneurs Andrew Ungerleider and Gay Dillingham co-founded Earthstone in 1993. Pumice is a volcanic rock used as an ingredient in concrete, as a mild abrasive in cosmetics and cleansers, and to abrade blue jeans, giving them their “stonewashed” look. Ungerleider, working with a ceramicist, found an alternative using recycled glass. It was a cost-effective and superior alternative, which was completely earth-friendly. Utilizing ground glass and carbonate mimicked a volcanic eruption inside the controlled environment of a large kiln. The result, “earthstone,” is ultra-lightweight, non-toxic, non-flammable, and insulative material with excellent compressive strength. It is also anti-microbial and completely sterile.

While the initial products were for consumer and industrial cleaning and sanding applications, continued development of the patented technology led to products for horticulture, water filtration, and green technology building materials. In scientific field tests at accredited third party facilities around the world, including the University of Arizona, the agricultural products have been shown to exceed the physical characteristics and performance of pumice and other commonly strip mined materials such as perlite, vermiculite, clay and stonewool or basalt.

Earthstone’s products reduce environmental impacts at both ends of the production chain. Besides replacing strip mined materials, the company found a way to give waste glass a new life – and keep it out of the landfill. Recycled glass bottles (mixed broken cullet) are turned into environmentally friendly cleaning products, abrasives, hydroponics substrates, container garden soil enhancers, and functional, affordable outdoor living accessories.

Earthstone has divided its business into two parts:

Earthstone International, LLC is focused on environmentally safe, foamed glass products used for household and commercial abrasives, and non-toxic heavy-duty cleaning, and holds patents for future applications such as building materials. The products are largely distributed through big box retailers and the internet. (www,

Growstone, LLC is focused on the sustainable horticulture and agriculture markets, and sells its innovative, environmentally friendly products to retail hydroponic stores, garden centers associated with big box stores, and to (primarily) commercial greenhouse growers. They use the “growstones” as a growing medium because they are highly efficient for moisture absorption, which allows them to reduce their watering cycles, and it brings oxygen to the root systems, both of which promote a healthy plant. Also, because the product is silica-based, some of the silica is gradually released, which also contributes to the plant’s health. Growstone’s horticultural products are reusable, recyclable, and adaptable to many growing systems, regional practices and climates.

Waste to Saleable Products

It is estimated that the total spent in the US each year just to transport waste to landfills reaches a staggering $50 billion. If we add the cost of collecting, hauling, sorting, disposing from construction, mining, industry, and agriculture, the price tops a staggering one trillion dollars, more than the entire 2009 federal stimulus package.

In 2008 Growstone, LLC entered into an agreement with the city of Albuquerque to process all of the waste glass from the city’s landfill and recycling program. Besides providing the glass waste for a nominal fee, the municipality has supplied a building to house Growstone’s glass crusher, and Growstone has recently completed construction of a production plant at the Cerro Colorado West Side landfill that can process 12,000 tons per year.

The glass is ground into a fine powder. A natural foaming agent is added, and it is then baked in natural gas-fired kilns into various sized lightweight growstones. “The product is created at roughly half the temperature and a tenth of the time required to create glass from silica,” explained Growstone CEO George Morandin. The natural gas is obtained by converting the landfill’s off-gas methane. (Landfill sites produce a tremendous amount of methane. Albuquerque has heretofore flared it off; a great waste of a resource, not to mention the greenhouse gas emissions being put into the atmosphere.) Growstone’s manufacturing process does not require water.

Additional applications for the Earthstone material are being tested. Some of the markets being developed include: engineered fill for roadbed construction and retaining walls, filtration for fish waste in fish farming plants, lightweight aggregate for soil stabilization in areas prone to mud or landslides, ultra-lightweight aggregate for concrete blocks and other cement-based products, underground thermal insulation for buildings and pipelines, and energy absorbing impact barriers.

Considering the thousands of tons of waste glass in landfills, and the cost to municipalities, this sort of recycling has tremendous potential. It may be a perfect marriage of public/private money because the municipalities supply what is, to them, waste. The company turns it into a salable product and green jobs.

Glass is heavy, and transportation expensive with a potentially large carbon footprint. The company’s long range plan is to establish a series of plants similar to the mid-size one in Albuquerque, 1,000–1,200 miles apart throughout North America, each with a 500-mile service radius. This could create a revenue source for municipalities, and make land adjacent to landfills useful.

Earthstone has evolved into a recognized leader in the growing international movement toward sustainable business practices. The company’s corporate mission includes returning a percentage of profits to worthy causes.

Stop Wasting the Waste

In his new book, The Blue Economy: 10 Years, 100 Innovations, 100 million jobs, noted eco-preneur Gunter Pauli addresses the issues of sustainability that go beyond mere preservation, and engage regeneration. Whenever we don’t know what to do with a waste, we discard it. That is antithetical to the way natural ecosystems operate. Making waste is not the problem. The problem is that we waste the waste we create.

Pauli’s team reviewed 3,000 cases in English, German, Spanish and Japanese publications to find which would present an opportunity to move industry and commerce toward sustainability independent of subsidies or tax breaks. The author submitted a shortlist of 340 technologies to a team of corporate strategists, expert financiers, investigative journalists and public policymakers. In Pauli’s book Earthstone/Growstone is cited as one of the 100 innovations that seize entrepreneurial opportunities that emulate ecosystems, and cascade energy and resources to add value and generate multiple exchange benefits, translating them into income and employment. Earthstone/Growstone is named #15 out of 100 inspiring competitive business models and #11 of 100 inspired by nature.

For more information, visit and

Seth Roffman is a writer and photojournalist. His work has appeared in the New York Times, the Christian Science Monitor, Native Peoples, Weekly Reader, New Mexico Magazine and other publications. He co-founded and edited a guide to sustainability in Santa Fe before becoming managing editor of Green Fire Times.


A Quick Primer on Glass Recycling

• Every two weeks Americans dispose of enough glass bottles and jars to fill up two tall skyscrapers. All of these jars are recyclable!

• A modern glass bottle would take 4,000 years or more to decompose – and even longer if it’s in the landfill.

• Recycling just one glass bottle saves enough energy to light a 100-watt light bulb for four hours, power a computer for 30 minutes, or a television for 20 minutes.

• Glass containers come in four different colors: clear, blue, brown and green. Glass must be separated by color to ensure that new glass is not created from a mix of colors. Earthstone does not have to separate the recycled glass by color to produce its products.

• Only about 28% of all glass bottles and jars are now recycled.

• Glass makes up about 8% of America’s municipal waste.


1. The Earthworks Group Recyclers Handbook (


3. Glass Packaging Institute (


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