Kelsey Lake Diamond Mine facts for kids
| Location | |
|---|---|
 Kelsey Lake Diamond Mine
Location in Colorado
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| Location | Larimer County, Colorado, 25 miles south of Laramie, Wyoming |
| State | Colorado |
| Country | United States |
| Coordinates | 40°59′38″N 105°30′18″W / 40.99389°N 105.50500°W |
| Production | |
| Products | Diamonds |
| History | |
| Opened | 1996 |
| Closed | 2001 |
The Kelsey Lake Diamond Mine was a special place in Colorado, USA. It was a mine where people looked for diamonds. This mine was located close to the Wyoming border. It had nine special rock formations called kimberlite volcanic pipes. These are like old volcano vents. Workers dug for diamonds in two of these pipes using an open pit method.
When it was open, the Kelsey Lake mine was the only modern diamond mine in the United States. It was also only the second mine in North America to dig for diamonds to sell. The first was in Crater of Diamonds State Park in Arkansas, which was mined a long time ago in the early 1900s.
Contents
History of the Kelsey Lake Diamond Mine
People became very interested in finding diamonds in the State Line Kimberlite District in 1976. They hoped to start a successful diamond mining business there. A geologist named Howard Coopersmith led a company called Diamond Co. They explored the Kelsey Lake area to see if mining diamonds would work.
Early Operations and Lawsuit
In 1995, an Australian company called Redaurum bought most of Diamond Co. Redaurum then rented the land around Kelsey Lake to start mining. They began digging for diamonds in May 1996.
After mining and selling about 200 carats of diamonds, Redaurum faced a problem. A company called Union Pacific Railroad sued them. Union Pacific had sold the land in 1896. But they said they still owned the rights to any minerals found there. The two companies worked out their disagreement. However, in September 1997, Redaurum decided to sell its diamond mines. They wanted to focus on finding new places to mine instead.
Changes in Ownership and Closure
The mine was used sometimes until a new company, McKenzie Bay International Ltd., bought it in 2000. McKenzie Bay bought the mine management company, Diamond Co., after it had financial problems (called Chapter 11 bankruptcy). They moved all its valuable things to a new part of their company called Great Western Diamond Co. McKenzie Bay also spent $2 million on new machines for the mine.
In 2001, McKenzie Bay tried to sell the mine. They wanted to focus on mining a different metal called vanadium, because its price went up a lot. But the sale didn't happen because of a disagreement with the landowner about payments. McKenzie Bay couldn't find another buyer. The mine stopped working in 2001. By 2006, the land was fully restored to its natural state. This process is called Mine reclamation.
Diamond Production at Kelsey Lake
Out of the nine volcanic pipes found at the mine, three had diamonds. Workers mined diamonds from two of these pipes, named KL-1 and KL-2. Each of these pipes was about 10.5 acres (4.2 ha) wide. They were also at least 350 feet (110 m) deep and were located about 0.5 miles (0.80 km) apart.
Diamond Recovery Rates
During early tests in 1990 and 1991, they found about 3.4 to 4.5 carats of diamonds for every hundred tons of rock. These were diamonds larger than 2 millimetres (0.079 in). About 50-65% of the diamonds found were gem quality. This means they were good enough to be used in jewelry. Also, 25-30% of those gem-quality diamonds were 1 carat (0.20 g) or larger.
When Redaurum ran the mine, it worked at half its possible speed. It produced almost 12,000 carats in 1996 and 9,000 carats in 1997. Redaurum also had mines in Africa that took most of their time and money. Because of this, the Kelsey Lake mine did not make a profit for them. McKenzie Bay later guessed that Redaurum's old machines only found diamonds in 40% of the rock they dug up. This meant they were only getting about 1.5 carats per hundred tons of rock.
Future Plans and Shift in Focus
When McKenzie Bay first took over, they thought their new machines could find 3.5 carats of diamonds for every hundred tons of rock. They also believed that each of the two pipes had about 340,000 carats of diamonds. They thought they could mine these diamonds for about 10 years and make a good profit.
The previous owners had an agreement with diamond sellers in Denver. They sold Kelsey Lake diamonds for $115 per carat. If McKenzie Bay had reached their goal of 60,000 carats per year, they expected to make $6.9 million each year. However, as the price of vanadium went up, McKenzie Bay decided to focus on that metal instead. They began the process of restoring the Kelsey Lake mine site in 2003.
Notable Diamonds from Kelsey Lake
The value of a diamond depends on its "4 C's": carat (weight), color, clarity, and cut. Bigger diamonds are usually worth more than many smaller ones that weigh the same. So, a successful diamond mine needs to find large, high-quality stones. The Kelsey Lake mine did find some very impressive diamonds.
Large Diamond Discoveries
In 1994, a beautiful white diamond weighing 14.2 carats was found. It was good enough to be a gem. At the time, it was the sixth-largest diamond ever found in North America. Experts said it was "almost flawless" and thought it was worth about $250,000.
In 1996, the biggest diamond found at the mine was discovered. It was named the "Colorado Diamond." This was a 28.3-carat (5.66 g) yellow stone. It was the fifth-largest diamond ever found in North America. A famous diamond cutter from New York, Bill Goldberg, cut and polished this gem. It became a 5.39-carat (1.078 g) sparkling stone that sold for $87,500.
In July 1997, the company found two more high-quality diamonds. They weighed 16.3 carats and 28.2 carats. The 28.2-carat diamond was cut into a 16.86-carat stone. This was one of the largest finished diamonds ever made in North America. It was even bigger than the gem made from the famous "Uncle Sam" diamond, which was cut into a 12.42-carat stone.
Images for kids
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Diamonds from a prospect in the State Line Kimberlite Field, Colorado-Wyoming
