Difference between revisions of "Carnelian"

Latest revision as of 11:04, 19 December 2022

Lentoid seal
MFA# 1971.173

Description

Carnelian amulets
MFA# 35.1500

A pale orange-red to deep red translucent stone that is a variety of Chalcedony. Carnelian was mined or gathered as an ornamental stone since at least 3000 BCE. It is found in Egypt, India and areas of Europe as water-worn pebbles. Carnelian was popular for amulets and scarabs and is still used as gemstones.

Carnelian cabochon

Synonyms and Related Terms

sard; cornelian; chalcedony; Karneol (Deut., Pol.); cornaline (Fr.); cornalina (Esp., Port.)

Physical and Chemical Properties

No visible crystals
Fracture = conchoidal, uneven, splintery
Cleavage = absent
Luster = waxy to vitreous
Streak = white
Fluorescence = generally inert
Pleochroism = absent

Composition	SiO2
Mohs Hardness	6.5-7.0
Density	2.58-2.68 g/ml
Refractive index	1.535 - 1.539
Birefringence	0.003 - 0.009

Comparisons

Properties of Common Gemstones

Resources and Citations

Mineralogy Database: Quartz
Encyclopedia Britannica, http://www.britannica.com Comment: "carnelian." Accessed 14 Sept. 2001 .
Gem Identification Lab Manual, Gemological Institute of America, 2016.
C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979
Wikipedia: Carnelian (Accessed Sept. 14, 2005 and Dec 2022)

@@ Line 12: / Line 12: @@
 * No visible crystals
 * Fracture = conchoidal, uneven, splintery
+* Cleavage = absent
 * Luster = waxy to vitreous
 * Streak = white
@@ Line 26: / Line 27: @@
 |-
 ! scope="row"| Density
-| 2.59-2.61 g/ml
+| 2.58-2.68 g/ml
 |-
 ! scope="row"| Refractive index
@@ Line 32: / Line 33: @@
 |-
 ! scope="row"| Birefringence
-| undetectable to 0.04
+| 0.003 - 0.009
 |}