CHAP. 25. (7.)—CARBUNCULUS: TWELVE VARIETIES OF IT.
In the first rank among these is carbunculus,[3076] so called from its resemblance to fire; though in reality it is proof against the action of that element:[3077] hence it is that some persons call these stones “acaustoi.”[3078] There are various kinds of carbunculus, the Indian and the Garamantic, for example, which last has been also called the Carchedonian,[3079] in compliment to the former opulence of Great Carthage.[3080] To these are added the Æthiopian and the Alabandic stones, the latter of which are found at Orthosia[3081] in Caria, but are cut and polished at Alabanda.[3082] In addition to this, each kind is subdivided into the male carbunculus and the female, the former of which is of a more striking brilliancy, the brightness of the latter being not so strong. In the male varieties too, we see some in which the fire is clearer than in others; while some, again, are of a darker[3083] hue, or else have their brilliancy more deeply seated, and shine with a more powerful lustre than others when viewed in the sun.
The most highly esteemed, however, is the amethyst-coloured[3084] stone, the fire at the extremity of which closely approaches the violet tint of amethystos: next in value to which, are the stones known as “syrtites,” radiant with a wavy, feathery,[3085] refulgence. They are found more particularly, it is said, where the reflection is most powerful of the rays of the sun. Satyrus says that the carbunculus[3086] of India has no lustre, that it is mostly soiled, and that in all cases its brilliancy is of a tawny complexion. The Æthiopian stones, he says, are dense, emit no lustre, and burn with a concentrated flame. According to Callistratus, the refulgence of this stone should be of a whitish hue, and, when placed upon a table, it should heighten by its lustre other stones placed near it that are clouded at the edge. Hence it is, that many writers speak of this stone as the white carbunculus, while the Indian stone, with its comparatively feeble lustre, is known by the name of “lignyzon.”[3087] The Carchedonian stones, they say, are of much smaller size than the others; but those of India admit of being hollowed out, and making vessels that will hold as much as one sextarius[3088] even.
According to Archelaüs, the Carchedonian carbunculus is of a more swarthy appearance than the others, but, when exposed to the light of the fire or sun, and viewed obliquely, the brilliancy of it is much more intense than that of the rest. He says, too, that this stone, when overshadowed by a roof, has a purple tint; that when viewed in the open air, it is of a flame colour; and that, when exposed to the rays of the sun, it scintillates. He states also that wax, if sealed with these stones, in the shade even, will melt. Many authors have asserted that the Indian stones are paler than the Carchedonian, and that, quite the converse of these last, they are all the less brilliant when viewed obliquely; as also, that in the male Carchedonian stone there are luminous points like stars within, while, in the case of the female stone, the whole of its refulgence is thrown beyond it. The stones of Alabanda too, it is said, are darker than the other kinds, and rough on the surface. In the vicinity also of Miletus, there are stones of this description found in the earth, resembling those of Alabanda in colour, and proof against the action of fire.
According to Theophrastus,[3089] these stones are to be found also at Orchomenus in Arcadia and in the Isle of Chios;[3090] the former[3091] of which are of a darker hue, and are used for making mirrors. He says too, that at Trœzen they are found of various colours and mottled with white spots, those found at Corinth being of a more pallid, whitish, hue. He states also, that they are sometimes imported from Massilia. Bocchus informs us in his writings, that these stones are extracted from the ground at Olisipo;[3092] at the cost of great labour, however, in consequence of the parched, argillaceous, nature of the soil.
CHAP. 26.—DEFECTS IN CARBUNCULUS, AND THE MODE OF TESTING IT.
Nothing is more difficult than to distinguish the several varieties of this stone, so great an opportunity do they afford to artistic skill of compelling them to reflect the colours of substances placed beneath. It is possible, they say, to heighten the brilliancy of dull stones, by steeping them for fourteen days in vinegar, this adventitious lustre being retained by them as many months. They are counterfeited, too, with great exactness in glass; but the difference may be detected with the touchstone; the same being the case also with other artificial stones, as the material is always of a softer nature and comparatively brittle. When thus tested by the stone, hard knots, too, are detected in them; and the weight of the glass counterfeit is always less. In some cases, too, they present small blisters within, which shine like silver.
CHAP. 27.—AHTHRACITIS.[3093]
There is also a fossil stone found in Thesprotia, known as “anthracitis,”[3094] and resembling a burning coal[3095] in appearance. Those who have stated that it is a native also of Liguria, are mistaken, in my opinion, unless perhaps it was to be found there in their time. Some of these stones, they say, are surrounded with a vein of white. Like those which we have mentioned above, they have a fiery colour, but there is this peculiarity in them, that when thrown into the fire they have all the appearance of becoming quenched and deadened; while, on the other hand, if they are drenched with water, they become doubly glowing.[3096]