Is Tungsten magnetic? I dropped my boyfriends ring (made of Tungsten) down the place in the doorframe where the door closes, not knowing there was actually a hole there.
Use commas to separate things in a list or series. If you have a series of three or more items, use commas to separate each item. Do not place commas before or after the list or series. Do not use commas when all the items in a series are linked by and, or, or nor.
Since commas are used in pairs to enclose phrases that interrupt a clause or that are intended to function parenthetically, a writer may choose to place a comma before and (or any of the seven coordinating conjunctions) when the conjunction launches such a phrase: