Volume 2

Conversations on mineralogy / With plates engraved by Mr. and Miss Lowry, from original drawings.

  • Varley, Delvalle
Date:
1826
Catalogue details

Licence: Public Domain Mark

Credit: Conversations on mineralogy / With plates engraved by Mr. and Miss Lowry, from original drawings. Source: Wellcome Collection.

    12/324 page 4
    MRS. L. Yes; near Madras, imbedded in granite; the corundum from the Carnatic is generally of a light greenish-grey, imbedded in indianite; and it oc- curs sometimes blue and red; but these colours are seldom bright, though the red always inclines to crimson. FRANCES. Here is a specimen, Mrs. L., of a delicate pink and blue; is it corundum ? MRS. L. Yes; that is a variety from Piedmont, which was discovered but a short time ago. When corundum is burnt it can be reduced to so fine a powder, that in India, where it is rather plentiful, it is rubbed upon razor-strops, or used instead of emery. FRANCES. Which is native emery, Mrs. L. ? I mean emery in its natural state. MRS. L. There are two kinds: this dark-brown variety is the most common ; it has a sandy appearance ; but the other is yery compact, with an uneven or splintery fracture, and is sometimes called diamond spar : the granular emery contains a good deal of the oxyde of iron. MARY. I do not admire either of them. Pray what is this very pale green crystal ?
    digitised image 1
    digitised image 2
    digitised image 3