If it ONLY had a Beta sign on it, chances are it was not a prescription drug (at least one made/sold in the US). All prescription drugs have a series of letters and numbers stamped or molded into them. Those identify the company that made the drug and, together with the color and shape of the pill, they identify exactly what the pill is. The combination of color, shape, markings are exclusive to that particular medication, made by that manufacturer and also identitfy the strength. Each company has to register the markings they use for each drug thjey manufacture. Non-prescription medication are marked in the same manner (like some Youth Strenght Motrin I had was marked with MO and 100).
One of the reasons for that is so if you do call poison control, they can identify the exact pill from your description by looking it up in the Physician's Desk Reference (PDR) which has complete descriptions of each pill and full size, color pictures of many medications.
I still would not want to find a pill on the floor of my room, but just wanted to point out the way medications are identified.