Arkansas, US (BBN)-A woman from Colorado, Bobbie Oskarson of Longmont, has discovered an 8.52-carat diamond, which she initially mistook for a quartz crystal due its size and shape, in a state park in Arkansas.

The gem, which a park staffer confirmed to be a diamond, was discovered in the Pig Pen, a 37-acre search field located within the Crater of Diamonds State Park. The name “Pig Pen” is derived from the terrain within the search field, as it becomes muddy when it rains.

The white diamond, roughly half the size of a quarter, is the fifth-largest diamond discovered by a visitor of the state park since 1972, Colorado’s Channel 2 News reported.

Oskarson, who plans to keep the gem, named it after her niece. She calls it the Esperanza Diamond. Park interpreter Waymon Cox was quoted by CNN as having said in a press release that “rain” and “regular plowing of the search field” increases the chances of visitors finding diamonds in the search area.

Just this year, there have been over 30 diamonds discovered in the park’s search area. But going back to 1906, there have been over 75,000 diamonds unearthed in the park, the largest of which being the Uncle Sam Diamond — a rough 40.23-carat diamond which was discovered back in 1924.

The Uncle Sam Diamond isn’t only the largest diamond ever discovered in Crater of Diamonds State Park, it’s also the largest ever discovered in the United States.

The search area where the Esperanza Diamond was recently discovered is one of the only publicly accessible diamond-producing sites and it exercises a “finders keepers” policy when it comes to discoveries such as Oskarson’s.

In other diamond news, a flawless 100-carat diamond mined by De Beers sold at Sotheby’s New York auction house back in April of this year for a staggering $22.1 million.

BBN/SK/AD