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.
The only time we put the commas or periods outside the quotation marks is when the item enclosed in quotation marks is a letter or numeral like A, or perhaps 4. British usage follows logic. American usage follows logic with question marks and exclamationpoints, but periods and commas always go inside quotation mrks.