How a grain of sand becomes 21 tons
What you’re looking for is Sugar Sand. No, we probably saw the last Sugar Sand here in 2017. Mike is telling me about the state of pure white silica sand in South Carolina. At that, South Carolina was one of the last places I was likely to find it. After spending the early winter months of 2020 attempting to track down matching sand to replace the thinning surface of the Sand Garden at the Asticou Azalea Garden, I found myself talking to a sort of sand cowboy as well versed in the finer points of specialty aggregates as anyone. By the time I reached him I had contacted over 50 different sand producing enterprises and had received so many samples I was running out of storage space.
The Sand Garden, in all its striking profundity, only works if the sand is just right. Mary Roper, the garden manager, had articulated the parameters: the grains need subangular edges in order to hang together and there needs to be a wide enough size gradient to hold sharp peaks while raking. The sand cannot be so fine that it is lost to wind and rain, nor so large that it is difficult to clean of seeds, leaves, and catkins from overhanging trees. It needs to be translucent so that light does not reflect directly off it, but rather makes it glow. Most importantly the color must be just so. White, not gray and not beige, appearing cool to the eye, almost blue in its pure whiteness.
Back in 1957, Charles Savage brought this exceptional sand to his garden from a mine in Berkeley Springs, West Virginia. At the time, the mine was owned by Pennsylvania Glass Sand Company. This was one of the first mines in America producing pure enough silica sand to make high quality glass. Through a series of mergers and acquisitions the company grew into U.S. Silica, now one of the largest producers in North America.
The current reality is that the Sand Garden is getting thin. After almost 70 years it is barely an inch deep in some places. This causes the rake to skip and wobble when it catches undulations in the underlayment. In places, there is not enough material to leave tall, beautiful peaks. Every week when it is cleaned and raked the sand is meticulously saved. Sand that comes out in the screening of fallen debris is lovingly separated, washed, dried, and set in storage, ready to patch up places that dearly need it. But even with such careful attention it is disappearing little by little.
Not that this was an unanticipated situation. As far back as the early 1990s garden associates made efforts to replace the sand. Most of these were unfortunate ideas, such as a proposal to replace it with chicken grit, which Tom Hall briefly pursued. By 1996 Mary found a bagged aquarium sand that matched precisely, but the priority for a full restoration of Savage’s Sand Garden had not yet been born.
How hard could it really be to match, though? I started asking this question in 2017 when I was halfway through my second year working at Asticou, and I was encouraged to take up the search. I was familiar with the subtle anxiety around our sand scarcity. How long could we limp along with our thin sand? How many more years until the skips and thin spots became glaringly apparent even to the untrained eye? As it turns out, not only was it genuinely hard to match but there were informed people along the way who made the whole enterprise sound impossible.
Eugene, a former gardener, fell into a conversation with a visitor in 2015 who turned out to be an aggregate consultant. Known as “The Sandman,” he helped people in industry and the arts find gravel and sand for specific projects. Mary had seen an art installation on the National Mall for which he had sourced the materials. I did some digging based on the scant information we had and managed to track him down. He loves this garden, and graciously agreed to try and match our sand. Dishearteningly, even this specialist was unable to find something that met all our specifications. However, he did run a sieve analysis on a bag of our matching aquarium sand, which gave us a language with which to communicate through a network of quarrymen.
The US Standard Sieve grading system is based on wire mesh, and how many holes are in a square inch. A number four has four holes per inch, able to pass through grains up to 4.76mm. Number 200 has 200 holes per square inch, each one just 0.074mm. What we were asking for was a 16/30. This is a mix with the largest grains being a 16 and the smallest a 30. Now I had shop talk, and could say something to producers like, “Yeah, I’m looking for a white silica sand, 16/30, not too gray or yellow.”
I started requesting samples from large, public facing silica corporations. Everything that came in was too gray, too large, too opaque, or something else outside of our baby-bear perfection. Even the original mine in West Virginia was producing opaque particles. Though matching in size and texture, the perfect vein of 1957 had long been depleted. The match that Mary had found in the 1990s was from an existing sand manufacturer but when she had tried to go through them in 2014, and again when I tried again in 2017, they were unable to give us the original source of that sand.
I was not the only one with sand problems. In May 2017, David Owen wrote an article in The New Yorker entitled “The World Is Running Out of Sand.” He reported that “the mining of sand and gravel greatly exceeds natural renewal rates.” Sand (or aggregate as it is known in the industrial world) makes up most of the concrete and asphalt used in the construction of our homes and buildings, our roads and parking lots. Sand is used by a myriad of industries including oil and gas drillers, foundries, and transportation. Sand is a component of glass products and cell phone screens. Water treatment systems use sand for filtration. Desert sand, which is plentiful in many parts of the world, is not suitable for construction or any other practical uses, Owen writes, due to the size and shape of the grains.
The situation is only getting more dire. In the silica sand industry in particular, the purest deposits are getting mined out. The next couple of decades could see the last of easy silica. All this was rattling around in my head last January. The urgency was both local and global. While Mary was engaged with other Sand Garden restoration concerns, I was at home by the woodstove with a few frozen months to myself. So, I started making some calls.
SiO2, or silicon dioxide, itself is abundant in the earth’s crust. In its purest form, think quartz, amethyst, and citrine (silica sand is also known as quartz sand). Silica often is bound to other molecules, forming minerals such as feldspar, mica, and garnet. The purest silica deposits can be used as a base for glass manufacturing. The purest of those are used to make silicon semiconductors -- computer chips.
What I needed to find was something of a geological anomaly. Yes, I wanted sand on the purer, glass quality side. But I also needed it the right size and shape. Hired consultants on the Sand Garden restoration project engaged a university team to find the geological “fingerprint,” but that just confirmed what historical records pointed to -- the now unsuitable mine in West Virginia.
When I was able to track down samples of the correct size, they were usually too yellow in color and thus too warm in tone or otherwise too gray and dark. This has to do with geological history. The younger silica deposits in North America are coarser and tend to have more iron, skewing the color. The older deposits have less iron but are of finer grain. When I talked with the head of the Minerals Research Laboratory in Asheville, North Carolina he understood my problems exactly. He was doubtful I could find what I was attempting.
By March I had a collection of sand from across the country. I began to contact producers within the same geological formations as promising deposits. Maybe they would be hitting a better vein than their neighbor. Across the Tennessee border from Berkeley Springs was no good. Neither were producers with large grains in Wisconsin. New Jersey was a bust. But it was when I was looking in South Carolina, near the now unsuitable deposit of the matching aquarium sand Mary found in 1996, that I got in touch with Mike.
“I know just what you’re looking for,” he said. Mike has been in the sand business for 30 years. He used to extract and sell “Sugar Sand” until it was nearly impossible to find. For the last twelve years he has been doing what I inadvertently wandered into: collecting sand samples and helping match needs to specific projects. He cast doubt on whether I would be able to find what I was after. But then he said, “Hold on now. I see that you’re calling from Maine. My wife and I love Maine. Where exactly are you?”
I told him Mount Desert Island and I could hear his tone brighten. He told me about one of the most powerful moments of his life up on top of Cadillac Mountain, how he had prayed that God show him the unadulterated beauty of creation and that when he looked out over Frenchman Bay and the Porcupine Islands, he said he felt like he could see God’s glory laid out right in front of him.
“That’s right where we are,” I said, “in the shadow of that mountain. The garden is designed to be in dialogue with that landscape.”
“You know,” Mike said, “maybe I can help you.”
He reviewed his sand collection and directed me to Florida. There is a supplier there who is still selling “Sugar Sand.” They sent us some samples. To sprinkle it on the surface and rake it into the Sand Garden is to watch it completely disappear. A rather perfect match.
We have ordered 21 tons to be delivered, a calculation based on the volume the Sand Garden holds and what a 53-foot dry van trailer can carry. That should be enough to last another 70 years at least. Maybe 170 more. With this we can move toward a complete restoration of Charles Savage’s incomparable Sand Garden.
Jacob Wartell, Gardener - Asticou Azalea Garden