My best guess is sometime centuries ago.......or just yesterday.
blazerdog, I can't speak for the other 124,819 members, but it's pretty much impossible to give a "time frame" of any thing in your pictures. I go along with kingskid's post, centuries ago....or just yesterday. Not saying what you have IS from yesterday, but allow me a short story here. Years ago working somewhere in N. Calif, there was a fella on the crew that as a hobby, would make arrowheads, knapping them the "old traditional way", very cool. Later that day while the crew was parked on a RR siding, me being me, began to wonder around way out there, low and behold a Forest service cop drove up, and of course asked what I was looking for etc., topic of arrowheads came up, not allowed etc, violation of acts etc, and I asked him, "Like this?", (I had one the guy gave me earlier) well....the officer came somewhat unglued, and I had to explain to him about how I happened to have it in my possession, which of course he did not accept, until I brought him up to the tracks, found the fella sitting on a man carrier, making "arrowheads", ( A wonderful moment for me), and I did tell the officer that yes, I'm sure the volcanic glass had some age to it, but the arrowhead? made Yesterday. Point is that in hand, a person handed two points, probably could not give a time period, 1000 years, or yesterday. Your posted pictures? well...looks like chips and chunks of obsidian to me, could be millions of years of age. I'm not being sarcastic, but you seem "ticked" that 124,820 members can't give a time period as to when the chunks became chunks? There are a lot of very sharp and knowledgeable people on T-Net in regards to arrowheads and such, but the pictures really give them nothing to go on I think.