Those are indeed “arrows.” You will also find you have “hearts” on the other side of your diamond, but these are hard to see without a scope (explained below) even with a loose stone.
H&A is a brand name that certifies that its diamonds will have a particularly well-cut hearts-and-arrows pattern (so from my perspective it is part-gimmick, part-substance). There are equally well-cut diamonds that don’t have the H&A brand-name that would, if H&A were able to get their hands on them, but not being owned by H&A, they don’t get to be called that. There are more of these than there are their identical twins who are owned by H&A and get the brand name “stamp,” though they are still rare. Yours might be one of them, but I can’t tell, from this information.
Many round brilliant diamonds have discernable arrow patterns. You can see arrow patterns on diamonds that wouldn’t necessarily meet the H&A criteria (for example you can see them on “very good” GIA cut grades, and maybe even lower cut grades), but of course you will definitely see them on H&A branded diamonds and other diamonds that have specs that would qualify them for the H&A brand.
To get a rough idea of whether yours might be as well-cut as an “H&A” brand diamond (or even better!), note your cut grade on your diamond’s cert: it should be the highest the grader will give, i.e., GIA triple-ex or AGS triple-zero.
If it meets that criteria you can already have a lot of confidence that your diamond cut is very beautiful indeed. Next check its HCA score, on the online HCA calculator. It should be less than 2.
Got a top grade cut diamond with an HCA score less than 2? You have a fantastic cut of diamond that sparkles as well or better than most H&A branded diamonds. Would yours get the H&A “stamp” if H&A would own that diamond? Very likely, but if you want to guarantee it, one final thing has to be done:
Get an idealscope/firescope/[fill-in-the-blank-brand]scope (like $20 on ebay) and check out the light return images produced by the diamond within the scope. You’ll find websites that will tell you what an H&A cut’s light return will look like, and what other light return images correspond to.
Of course, if you didn’t buy your diamond from H&A brand, it’s not an H&A brand diamond. Then again, if you’ve got a diamond that’s at the highest cut grade from GIA or AGS and and HCA score of less than 2? Who the heck cares! You have one of the most well-cut diamonds out there in existence, easily matching and exceeding some H&As for their cut’s beauty.
Hope this helps!