The 2018 $50 Gold Eagle is considered a Burnished Gold coin. The US Mint makes three different surfaces for the Gold Eagle coins that they make each year. All of them are 1oz 999 fine 100% Gold. They make a Mint State BU Gold Eagle, a Proof Gold Eagle and a Burnished Gold Eagle. The difference with the Burnished is it’s more of a satin finish on the coin. For the Burnished coins it is specified as SP70 ( Specimen Proof ) it also bears the W Mint Mark on the coin that stands for the West Point Mint In NY. This coin is graded by PCGS and was purchased at the US Mint store in Denver. The US Mint had three location stores, one in Philadelphia, Washington DC and Denver. These stores took on foot traffic. When a coin was released someone would have to physically be online at 12 noon when they opened their doors. Coins that were purchased at location stores are very rare. Since March of 2020 all three location stores have been closed due to Covid 19