GEMMA
GEMMA a gem or precious stone (Greek,
λίθος: there is no Greek word for gems as distinguished from
ordinary stones. On the supposed rule of the grammarians that
λίθος, a precious stone, is feminine, consult
Liddell and Scott, s. v.).
[p. 1.902]
The desire to possess the precious or semiprecious stones, whether as
ornaments or as objects of superstition, is universally prevalent. In any
nation, however, it is limited by the geographical conditions, and by the
degree of mechanical skill available. At the early stage of civilisation
represented on Greek soil by the graves of Mycenae and kindred deposits, the
stones found are of no great rarity, but are shaped and polished in a way
that proves considerable mastery over hard materials. Thus objects of agate,
rock-crystal, sard, and amethyst are elaborately worked and engraved.
(Schliemann,
Mycenae, figs. 307-315; Lolling,
Kuppelgrab bei Menidi, pl. vi.;
Cat. of Gems in
Brit. Mus. 104-109.) In Homer, however, there are no traces of
the use of gems, as there is not any good reason for supposing them to be
intended by the
ἕρματα πρίγληνα μορόεντα
of
Iliad, 14.182;
Od.
18.297. (See Buchholz,
Homerische Realien, ii. p.
214.) It has long been observed that Homer was unacquainted with the use of
seals (Pliny,
Plin. Nat. 33.12), and the
nearest approach in Homer to the use of gems as ornaments is the employment
of the attractive and easily worked amber in jewellery (
Od. 15.460,
18.295; Helbig,
Das homerische Epos, p. 183). From
these facts it may be inferred that the art of working in hard stones was
lost after the Mycenaean period; and this conclusion is confirmed by
statistics as to the very early gems known as the “gems of the
Islands” [see
SCALPTURA]. These gems are found both among Mycenaean and early Greek
deposits. But while in the former case they are often of the hard stones
mentioned above, in the latter case they are of soft materials, such as
steatite. (See Dümmler,
Mittheilungen des Arch. Inst. in
Athen, xi. p. 177.)
The Greeks of historical times had a restricted choice of precious stones,
until the conquests of Alexander had opened up intercourse with India. The
stone of Polycrates was an emerald, according to Herodotus (
3.41); but a sardonyx, according to Pliny (
Plin. Nat. 37.4). In the treasure lists of
the temples of the Acropolis of Athens, the only gems mentioned are the
jasper, sard, and onyx, together with the
χρυσίτης
λίθος, or gold ore. (Compare with this list Plato,
Phaedo, 110 D,
τὰ
ἀγαπώμενα, . . . σάρδιά τε καὶ ἰάσπιδας καὶ
σμαράγδους.) The gems mentioned in the treasure lists were for
the most part set in rings or used as seals, and were therefore of small
size. An onyx, however, is mentioned in a list for 398 B.C., which
represented a
τραγέλαφος and weighed 5 oz.
(
C. I. A. 652 b, 50.12). Another onyx is mentioned in the
list for 385 B.C. (
C. I. a. 667, 50.20), which apparently
weighed 42 oz. (But cf. Boeckh,
Staatshaushaltung, ii.3 247.) Perhaps one of these stones is the “great
onyx” reported as broken in the list for 344 B.C. (
C. I.
A. 701, 50.57; cf.
C. I. A. 676, 50.18).
The state of knowledge as to gems about the time of Alexander is represented
by the work of Theophrastus
Περὶ Λίθων,
the only surviving systematic treatise on the subject in Greek. Though
written in 315 B.C., the book has not felt the
influence of Alexander's campaigns. Theophrastus surveys, however, the whole
basin of the Mediterranean, and Asia Minor. He makes one allusion to
Bactria, and a doubtful one to India. The number of gems available for the
engraver is now become considerable. Theophrastus enumerates among stones
suitable for engraving the emerald, sard, carbuncle (
ἄνθραξ), lapis-lazuli (
σάπφειρος: see below), jacinth (
λυγκούριον), topaz [?] (
ὑαλοειδής), chrysoprase [?] (
ὄμφαξ, rock-crystal, and amethyst. Among the lost works of
Aristotle was a treatise with the same title as that of Theophrastus, of
very doubtful authenticity. (Heitz,
Die
verlorenen Schriften des Aristoteles.)
For accounts of the extraordinary profusion of precious stones in the East,
and among the successors of Alexander, compare
Diod.
18.26; Athenaeus, xi. p. 781;
Strabo
xv. p.718, and other passages quoted by Krause,
Pyrgoteles, p. 113. The extravagant luxury of the
Romans of the Empire rivalled that of the Diadochi. Thus Heliogabalus wore
gems engraved by the best artists, on his shoes. (Lamprid.
Heliog. 23; cf.
Plin. Nat.
9.117, and other passages quoted by Krause,
Pyrgoteles, p. 114.)
This passion on the part of the wealthy for precious stones was naturally
favourable to the growth of mineralogical knowledge. Pliny quotes a large
number of writers who had treated of gems between Theophrastus and himself.
Some of these writers (as Zenothemis,
Plin. Nat.
37.87) seem to have had a personal knowledge of India (cf. King,
Precious Stones, p. 1). Pliny devotes the 37th or final
book of his Natural History to gems, regarding them as the most perfect
works of nature. The book consists of an historical introduction (
§ § 1-5); of an account of the most important gems,
arranged by colours ( § § 6-54); of an account of minor
gems in alphabetical order. The book concludes with a few general
instructions for detecting fraud. This book is the best representative of
ancient science in this branch of mineralogy. In attempting to form from it
an estimate of the ancient science, we must neglect the false medicine,
sometimes rejected by Pliny (
Plin. Nat.
37.53), the magical superstitions, and the trade mysteries (cf.
H. N. 37.57, on the difficulty of breaking diamonds). We
then find that the ancients were remarkably close observers of gems,
availing themselves of all methods, short of chemical analysis and other
instruments of modern physical research. It is said of Democritus that
“ne lapidum . . . vis lateret, aetatem inter experimenta
consumpsit” (Petron.
Sat. 100.88).
Moreover, in the case of precious stones, minuteness of observation was
stimulated by the desire of guarding against or of committing a fraud
(
H. N. 37.197 ff.). Besides a minute study of colours of
gems, frequently illustrated by Pliny's felicitous comparisons, the tests
enumerated involve a study of weight (
H. N. 37. §
§ 98, 199), consistency (
corpore,
§ 199), hardness ( § § 98, 113, 200),
conductivity ( § § 128, 199), transparency ( §
198 and
passim), diffractive power ( §
§ 87, 136), friction ( § 189), crystallography (
§ § 26, 56, 76, 137, 144, 171, 178), taste ( §
§ 162, 173), and smell ( § § 139, 145, 147, 174,
185).
There are no traces in Theophrastus of magical properties attributed to gems.
In Pliny, the doctrines of the
Magi are
frequently quoted, but usually with ridicule. (Cf.
H. N.
[p. 1.903]37. § § 118, 142 ff. and
passim.) Some of the medicinal virtues of
gems apparently accepted by Pliny, may appear little better than the
doctrines of the Magi. But while Pliny is not in a position to criticise the
alleged virtues of gems applied as medicines, he consistently rejects their
supernatural powers under other conditions. The magical system is seen fully
developed in the
Lithica of Orpheus. This poem claims to be a
statement of the magic properties of gems made by the seer Theodamas to the
poet Orpheus. The work is assigned by Tyrwhitt to a time subsequent to the
edict of Constantius against magic, in 357 A.D. (cf. lines 73, 74), and not
long after Valens. (Tyrwhitt,
Περὶ λίθων,
poema Orpheo adscriptum, London, 1781.) In this
view Tyrwhitt is followed by subsequent editors, although Krause (
Pyrgoteles, p. 6) assigns the work to the 5th
century B.C.; and King (
Precious
Stones, pp. 4, 397) dates it “at least as early as the 2nd
century B.C.” King gives an English verse translation
(
Precious Stones, p. 375).
On the later developments of the magical system of Orpheus until mediaeval
times, see King,
Precious Stones, p. 6.
Much confusion and uncertainty exist as to the true nomenclature of gems.
Both in ancient and modern times there has been considerable looseness of
usage as to the meaning of names. In many instances where the ancient word
exists in modern language, it denotes a stone entirely different from that
originally signified. For example,
σάπφειρος is certainly the
lapislazuli,
and has no connexion with the sapphire. The correct equivalents of the
ancient names are generally given after King and others, in Liddell and
Scott's Lexicon (ed. 7).
Literature.--Krause,
Pyrgoteles, oder die edlen Steine
der Alten (learned, but untrustworthy); Lenz,
Mineralogie
der alten Griechen und Romer, Gotha, 1861; C. W. King,
Natural History of Precious Stones and Gems, and of Precious
Metals, London, 1865; Blümner,
Technologie, 3.227. On the use of gems in rings, see ANULUS; on the art of gem engraving, see
SCALPTURA
[
A.H.S]