The word “jewel” first came into use without any reference to personal adornment. The jouel, or joyau, was the golden centerpiece on a king’s feast table. The word didn’t apply to gold and gems fastened onto clothing and hair until the late 14th century, where its use apparently began in the court of the Duke of Burgundy.
In early medieval times, European jewelry was a brooch or a ring. That is, either it fastened your cloak or it slipped onto your arm or finger. Clothing was heavy, since the distinction between outerwear and daily wear was not very big in a time of unheated rooms. Most fasteners we know today had not yet been developed; clothing was laced or fastened with brooches. Men used brooches as much as or more than women, so in this time, wearing a brooch carried no gender marking at all. Brooches for men and women were identical.
Arm rings had no practical purpose, but they were the chief means of “portable property” (to borrow a phrase from Dickens). When a Germanic king honored a warrior, he gave him an arm ring. The inner chamber of the king’s hall held a locked chest filled with arm rings. They were taken as spoils in raids, or they were made fresh by melting down gold or silver seized in other forms, like coins. Early Europe did not value gold, or even silver, chiefly for its purchasing power. Precious metals were for arm rings, visible signs of honor.
The story of jewelry in medieval Europe is essentially the same story as everything else: the late Roman Empire had a certain level of industry, learning, wealth and civilization that was disrupted by multiple barbarian invasions. Roman arts lived on in Byzantium, or Constantinople as the city was now called. To the west and north, however, those arts could only be glimpsed now and then. Travelers brought back reports or small tokens of New Rome’s beauties. Barbarian smiths, tailors, and carpenters tried to imitate Byzantine things. At first, their attempts ranged from silly to charming to pathetic. Gradually, the north and west caught up. Eventually, they surpassed Constantinople. The moment of catching up and passing is, effectively, the close of the Middle Ages and the beginning of what we know as the Renaissance.