No, this is not LR. It will take some time, in your tank, before it becomes LR. Base rock is dead with respect to the definition of LR, but it's not called dead rock, it's called base rock. Many people use base rock to bulk out the reef. Usually, it's used underneath LR, with the understanding that it will become LR in time as the organism from your LR multiply and colonize the base rock. It is not to be a substitute for LR.
LR that comes from the ocean and has been collected and shipped properly has had years to develope the infauna and life that can only come from the ocean. Both macroscopic and microscopic life is found in/on LR. This base rock, although pretty and will help build your aquascape, initially, will do little to nothing for your biofiltration.
I mentioned earlier about
www.tampabaysaltwater.com. This LR is aquacultured off the coast of Florida and is collected and shipped underwater. It has very little die off as a result and is a unique shipping method. As a result, it costs more but with this LR, you'd be amazed at the life that comes out of it. In esssence its what you wanted to do-collect your own. Anyway, you may have opted against this because of finances, but I use it demonstrate what constitutes LR. IMO, this is the most "alive" you can get LR without collecting it yourself! I recommended it because your tank was already mature, it just needed a little more biofiltration in the form of LR. You can also get live sand from this company. Sand that was scooped right out of the Gulf of Mexico and shipped in water. It's teaming with life.