You see both of these placenames on many maps. If you go to Google Earth, they’re both easily located, just by typing the names in search. Silvacola has a zip code: 37617. This picture shows the location shown on Google Earth for this community. As you drive down Market Street, which roughly parallels US Highway 11W, going east, you’ll see remnants of what must have been a reasonably thriving area many years ago. This is the intersection of Market Street and Harr Town Road, which I now have the merit badge (sort of) for driving from one end to the other (at Hwy. 126). Zippy!
Now, on to Spurgeon, which is in Washington County. Google Earth and the U.S. Census Bureau differ as to the exact location of Spurgeon. This is the Google Earth location (the grove of trees in the picture), which is .41 mile south east of where the Census Bureau locates it. This is on Gray Station Road, just off Hwy. 36. About .91 mile to the east of here, below Boone Dam, is Spurgeon Island, which doesn’t look like an island to me, but maybe it was before the early ’50s when the dam was built. There’s also a Spurgeon Gap Road nearby.
Spurgeon does not now have a zip code. Poor Spurgeon.