’tis not impossible that there may be Stones as much more susceptible than that, of the Alterations requisite to make a Diamond shine, as that appeares to be more susceptible of them, than ordinary Diamonds.  And I confess to you, that this is not the only odd suspition (for they are not so much as conjectures) that what I try’d upon this Diamond suggested to me.  For not here to entertain you with the changes I think may be effected ev’n in harder sorts of Stones, by wayes not vulgar, nor very promising, because I may elsewhere have occasion to speak of them, and this Letter is but too Prolix already, that which I shall now acknowledge to you is, That I began to doubt whether there may not in some Cases be some Truth in what is said of the right Turquois, that it often changes Colour as the wearer is Sick or Well, and manifestly loses its splendor at his Death.  For when I found that ev’n the warmth of an Affriction that lasted not above a quarter of a minute, Nay, that of my Body, (whose Constitution you know is none of the hottest) would make a manifest change in the solidest of Stones a Diamond, it seem’d not impossible, that certain warm and Saline steams issuing from the Body of a living man, may by their plenty or paucity, or by their peculiar Nature, or by the total absence of them, diversifie the Colour, and the splendor of so soft a Stone as the Turquois.  And though I admir’d to see, that I know not how many Men otherwise Learn’d, should confidently ascribe to Jewels such Virtues as seem no way competible to Inanimate Agents, if to any Corporeal ones at all, yet as to what is affirm’d concerning the Turquois’s changing Colour, I know not well how to reject the Affirmation of so Learned (and which in this case is much more considerable) so Judicious a Lapidary as Boetius de Boot[31], who upon his own particular and repeated Experience delivers so memorable a Narrative of the Turquois’s changing Colour, that I cannot but think it worth your Perusal, especially since a much later and very Experienc’d Author, Olaus Wormius,[32] where he treats of that Stone, Confirms it with this Testimony. Imprimis memorandum exemplum quod Anshelmus Boetius de seipso refert, tam mutati Coloris, quam a casu preservationis.  Cui & ipse haud dissimile adferre possum, nisi ex Anshelmo petitum quis putaret. I remember that I saw two or three years since a Turcois (worn in a Ring) wherein there were some small spots, which the Virtuoso whose it was asur’d me he had observ’d to grow sometimes greater sometimes less, and to be sometimes in one part of the Stone, sometimes in another.  And I having encourag’d to make Pictures from time to time of the Stone, and of the Situation of the cloudy parts, thatso their Motion may be more indisputable, and better observ’d, he came to me about the midle of this very week, and assur’d me that he had, as I wish’d, made from time to time Schemes or Pictures of the differing parts of the Stone, whereby the several Removes and motions