Silent egg-shaped golden-copper object

There I was, in my room, listening to music with headphones on. I was looking out the window at the time. The sky was blue, and there were no clouds. The winds were calm as well. Then, I noticed an egg-shaped object that was slowly moving at about 15 MPH in a northerly direction, horizontally. It was about 150 feet above the water. Its distance from me was approximately less than a mile. I took my headphones off and got out of my room and continued to observe the object which seemed to be a goldish copper. The sun glistened on the front of the object, reflecting the light as if the object was made of some sort of metal.Another curious thing that I noticed was that there was no sound coming from it as it moved. It was perfectly silent. No type of engine was protruding from the object and I could hear the birds chirping in the trees. The object continued it's slow, northerly track until it disappeared from view. The event lasted approximately three minutes at the most.
I am a believer of UFOs and have had dreams about them. However, I took the position of a skeptic and rationalized the event as I watched the object, and asked myself the following questions: is it a new type of private or commercial airplane, hot air balloon, helicopter, a blimp, a cloud, a new type of weather balloon, a hanglider. None of these applied to this object. All the crafts I have mentioned could have been easily identified had they been at the location where the object was traveling because we were always able to see Cessnas and helicopters fly close by, and we could hear them over a mile away. But this object was quiet and entirely different. It did not resemble anything known to me.
Date is approximate.  PD