Here's one of the coolest pieces of ice you'll ever see ... a jeweler made a custom diamond pendant of Colin Kaepernick kneeling -- and he's set to sell it for charity!!!
Moses The Jeweler in NYC created the piece ... and it's insane. TMZ Sports has learned it cost $90,000 to make, and it was produced with 18k yellow gold.
We're told it also has VVS hearts and arrow cut diamonds -- and took A YEAR to create.
Of course, the jewelry is a replication of the famous moment when Kaepernick first began kneeling for the national anthem as a member of the 49ers back in 2016.