1871 G California Gold Half Dollar

Looks like a replica to me.

It appears to be a genuine but damaged example of BG-1025 (1871 50 cents with G below bust, round Liberty Head, last L in CAL is raised)

The gold content of these varied widely from 5kt-14kt or more. Most never saw any actual circulation and were made and sold as souvenirs, sometimes made as late as the early 20th c. and "backdated" to 1854/1871/etc.

However, the "G" on yours is for its maker, Robert B. Gray & Co., and their pieces were known to be contemporary (in other words, your 1871 was probably made in 1871.)

The use of an XRF machine would be needed to determine its precious metal content. These do have a collector market, and can be certified by PCGS and NGC, but the damage to the coin will substantially reduce its value. This particular variety is quite scarce (R5 rarity) and if it tests as being gold, worthy of a PCGS or NGC third-party grading submission to be "slabbed."

By the way,

to CCF!