What Wikipedia says

Thasos or Thassos is a Greek island, geographically part of the North Aegean Sea, but administratively part of the Kavala regional unit. It is the northernmost Greek island, and 12th largest by area. Thasos is also the name of the largest town of the island (officially known "Port of Thasos"), situated at the northern side. The terrain is mountainous but not particularly rugged, rising gradually from coast to centre. The highest peak is Ypsario (Ipsario), at 1,205 metres (3,953 feet), somewhat east of centre. Pine forest covers much of the island's eastern slopes.

The island was colonised at an early date by Phoenicians, attracted probably by its gold mines; they founded a temple to the god Melqart, whom the Greeks identified as "Tyrian Heracles", and whose cult was merged with Heracles in the course of the island's Hellenization. The temple still existed in the time of Herodotus. An eponymous Thasos, son of Phoenix (or of Agenor, as Pausanias reported) was said to have been the leader of the Phoenicians, and to have given his name to the island.

The writer Vassilis Vassilikos, famous for his novel "Z", which was later adapted into an Academy Award-winning film was born in Thasos in 1934. He later became Director General of Greek Public Television, and Greece's ambassador to UNESCO.

By far the most important economic activity is tourism. The main agricultural products on the island are honey, almonds, walnuts, olives (famously Throuba olives), and olive oil, as well as wine, sheep, goat herding, and fishing. Other industries are lumber and mining which includes lead, zinc, and marble, especially in the Panagia area where one of the mountains near the Thracian Sea has a large marble quarry. The marble quarries in the south (in the area of Aliki), now abandoned, were mined during ancient times.