CHALCEDONY- AGATE, CARNELIAN, CHRYSOPRASE, ONYX, JASPER, OTHER COLOURS

Chalcedony consists of a group of cryptocrystalline  (microscopically small crystals) quartz. They include the above mentioned as well as the violet blue, white, yellow variety. Whereas crystal quartzes (rock crystal, amethyst, citrine etc) have vitreous lustre, chalcedonies are, in their natural state, waxy and dull. Named probably after an ancient town at the Bosphorus. Always porous, they can be dyed. Deposits are found in Brazil, India, Sri Lanka, California, east and southern Africa etc.

Agate and fireagate – all colours, banded. Distinct iridescent colours of  firegate caused by layers of iron oxide within the quartz. Arizona and Mexico.

g ag ovc roybl 38.53(22x17.4x10.5)tl  350 10b51 sold	h1 ag prc lmgn br 25.12(29x20x6.4)tp 200 10b51 N21
h2 fireag ov ogybn mx 17.66(23x17x6) 100 10b52 M26	l1 ag dinobone ov pp 9.92(22.3x13.6x4) 100 10b51M10
l1 ag rn hny br 9.21(14.3x9.3)tp  150 10b53 N25	l2 ag em hny br 7.29(14.6x11x7)tp 150 10b53 N21
m2 fireag fn yo us 3.84(13.2x9.4x4.1) 50 10b52 C2	m3 fireag ovfn ogy mx 2.01(9.7x7.9x3) 50 10b52 C5

Carnelian (also called Cornelian) after the kornel cherry;  Translucent, reddish orange variety of chalcedony. Best comes from India. Most today is stained and comes from Brazil or Uruguay.

l1 crn ov rdo cz 8.12(16.2x12.3x5.9)c 120 10b55 L8	l3 crn ov rd in 6.50(16x12x5) 100 10b55 N4
l crn ov rd af 5.90(14x10x5.4)c 100 10b55 N17	m3 crn rn rdbn slv 2.76(8x3.8)c 100 10b55 N6

Chrysoprase/Prase, the green or apple green is the most prized variety of chalcedony. Colour derives from presence of nickel. Used as cabochon, for necklaces and ornamental objects. Australia, Brazil, India.

e prs pr apgn af 51.61(28x22x16)ec 200 wb1 L42	h3 prs em imgn ta 14.41(18x12.9x8.6)op 200 10b59 N31
h2 prs ov ygn ta 15.0(20x15.2x7.5)op 200 10b59 N40	l prs ovc gsgn af 5.46(13.7x10.1x5.3)c 100 10b59 M4
m1 prs ov gn 4.21(12x10x5)c 150 10b59 CN10	m3 prs ov apgn au 2.95(10.2x8.2x4.8)tl    100 10b59 M3

Jasper, Greek for spotted stone, comes in variety of colours often mixed. Believed to protect sight and drought. Some varieties called red and riband (striped) jasper. Used in carvings and cameos. India, Venezuela, USA, Russia.

e1a js ov m-c ch 64.65(39x30x7.2) 200 wb1 M20	e1 js ovc gybn ch 66.56(40x30x7) 200 wb1 M20
e js ovc1 mcrd lf 54.43(40x30x6.3)pr300 10b41 N12	e js ovc2 mcrd rt 54.14(40x30x6.2)pr300 10b41 N12
g1 js ovc rdo in 45.80(29x22x8.7) 300 10b55 T41	h1 js ovc rd saf 23.36(24x18.5x5.7)op 200 10b52 C4
g js ovc crwh-bkspots af 35.70(25x18.5x9) 150 10b60 C4	h1 js prc mc-bksp af 22.96(21x20x7.4)op 100 10b60 C4

Onyx,  usually black, Greek origin for “fingernail”, probably due to weak transparency. Similar to agate but has straight than curved bands; these may be brown-white or black-white. Are usually carved as small sculptures and intaglios, or may be polished into beads or cut en cabochon. Found worldwide.

d ox egg dkgn wh line 1,233.22ct 250 L50	e ox tge bk th 59.48(52x10.6x9.4) 220 N23
h1 ox pr bk th 27.2(23x17x9.1) 200 10b54 N18	h1 ox ov bk 24.55(25x18x7.7) 200 10b54 N10
l3 ox rn bk 6.80(12.3x6) 150 10b54 C6	m2 ox ov bk 3.0(12.5x10.5x3.7)c 100 10b54 N11
	vs ox ht bk 1.20(6x6)c pair 100 10b54 N17

Blue/violet chalcedony - waxy lustre, translucent cut en cabochon. 

e1 cha ovc vi afg 83.10(31x26x15.4)tpu 500 wb3 LN23	g1 cha ovc lv ma 43.40(24x19.1x13.7)cu 300 10b56 N30
h cha ovc blpp in 11.55(18x13x7.2)tl 200 10b56 N21	l1 cha ovc plvi vi 9.09(16x13.3x7)trp 300 10b56 T60
l1 cha prc plvi vi 9.20(21x12.4x5.8)trp 300 10b56 T40	l cha trc plvi vi 5.34(12.1x6.7)nat 250 10b56 T45
l cha flw plvibl 5.65(15x4.3)c 200 10b57 N21

White and yellow chalcedony waxy lustre, translucent, cut en cabochon

g cha ovc wh bltt 36.0(30x21x7.4)c 300 10b57 L4	l1 cha ovc wh 9.60(16.1x13.2x6.7)trl 150 10b57 N7
l2 cha prc wh 7.14(15.1x11.1x6.7)trl 100 10b57 N9	m1 cha ovc y af 4.40(12.1x10.1x5)ec 100 10b57 N4