Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: having never owned a firepit I really don't understand the concept of the glass.  Can someone explain how it is used?  Thanks.
Document: it sits in my garage never used it may send it back not quite what I wanted. may need gas line to fire pit not sure!
Nice small pieces and really didn't find sharps like some of the reviews said. Yes, get at least two--maybe more if you want to fill a typical fire pit/fire table space. I used lava rocks around the edge of the fire pan and glass in the center. One bag  was fine for that but I ordered 2 and will probably use the second one to really cover the whole area. Very pretty looking even when there is no fire.
We initially underestimated the amount we needed to fill the firepit, but once in, it looks fantastic.The reflective glass looks really pretty whether the fire is on or off.
Ten pounds in not a lot. I didn't really know how much to get. My firepit table probably needs 30 pounds or so. Maybe it was just me but I didn't know how much to buy. The color is really pretty though and it sets well with red brick.
This was the perfect choice for our firepit. The color matches well and it really gives off a great sparkle
I bought two bags of this and put them around my firepit gas logs, The effect is beautiful, especially at night when the glow of the fire bounces off the glass. It provides that extra elegant bling around the flames!
Looks great...10 pounds is not enough for any firepit that I have seen. Mine is 18 x 18 inches and 2 inches deep, we put cheaper lava rocks on the bottom and covered them with this glass and it still is no where near enough. Get 30 pounds and save a little money up front.
THIS S*** LOOKS LIKE SORCERY. No, seriously, never have I more felt like a mage or sorcerer than when this was around. Put four torches around the table and play some D&D Outside for maximum effect.
I love the way this glass makes the firepit look and works. The flames dance around the glass area, relaxing and pleasing to the eye. Adds touch of class to the firepit, much better than the ceramic stone and logs that came with our gas firepit. Our pit required about 16-lbs of glass. I put the glass on top of the ceramic pieces and it required less glass. There is enough glass covering the ceramic pieces you don't see the cheaper pieces.The look won't disappoint you and the copper doesn't show fire residue from the flame.
Looks great in the Camp Monterey firepit, but make sure you buy 2 units to fill it adequately.
Answer: If you haven't seen the visual effect and the cool factor of watching a flame come out of bed of glass you should watch a youtube or DIY show with the remodel effect of a firepit or fireplace with glass in place of fake logs. It is a nicer experience with warmth and beauty as you relax around a fire with a loved one during evening time. We filled a gas firepit with glass replacing the ceramic logs, much better look and enjoyment. H