Send it for fire assay or try https://www.911metallurgist.com/blog/blowpipe-analysis-for-testing-minerals and http://goldminingandprospecting.blogspot.ca/2011/02/testing-for-gold-with-blowpipe-analysis.html

Do you have a metal detector?  Otherwise, borrow one of the small "pinpointer" models from someone.  Perhaps a prospector supplies store will let you borrow theirs for a few minutes.  If it doesn't contain anything that registers as a metal, then it's very unlikely that you have gold.  Another simple test:  Crush the sample into quartz sand with a mortar & pestle, then use a gold pan to separate the material by specific gravity.  Gold metal should be heavy enough that it won't move when sand and water are gently swirled around the bottom of the pan.  NB!  DON'T throw away the water you use or any of the sand, so you won't lose your material by accident.  But if you want a definite answer, then pay to have it fire-assayed, as Raje suggests. Even if you send it away to be assayed.  Purify it a little.  WEIGH the crude sand, then pan it as I suggested above, remove and dry the concentrated sample and weigh it.  Then send it to an assayer.  The higher the gold concentration in the sample, the better the accuracy of the result. When the assay result is returned, multiply the concentration they provide by the crude weight divided by the weight of the concentrate you sent them.  That will give you the concentration of any gold in your raw sand.  

Good luck.

If you don't want to destroy the sample, fire assay would be the best, have a competent mineralogist look at it. He may be able to tell by looking.