AFRIGEMTEC - SOUTH AFRICAN GEMS AND MINERALS

AGATE LOCATIONS IN SOUTH AFRICA

The Drakensberg basalts contain a variety of agates, which erode from its outcrops within Kwa Zulu Natal, Eastern Cape, Free State and Lesotho. This is an extremely slow source of a constant supply as the erosion takes place.

Agates also occur in the alluvial sediments of the Orange, Vaal, Limpopo and Caledon Rivers. These are mined for diamonds, and the agates are deposited on the dumps. There will be no further supply once the known deposits are exhausted.

1. BLOEMHOF

Alluvial diamond diggings along the Vaal River. Hand excavations 1 to 2 metres deep. Mining abandoned 30 years ago. The agates were transported by the Vaal River together with other gemstones and diamonds. It is not known where these agates originated.

1.1.	AGATE
	Black to dark brown outside, deep pitted, often eroded by water or outside layers broken or partly broken away. Banded in white, grey, brown and black within grey or brown translucent chalcedony. Also horizontal lines. Centre of cavity often filled with quartz crystals.

Size

»	fragments	10 to 40mm
»	complete agates	40 to 90mm
»	most common size	50 to 60mm

1.2.	MOSS AGATE
	Brown to dark brown outside, smooth, eroded by water. Inside brownish transparent to translucent with colour inclusions and organic looking patterns in various colours.

Size

»	fragments	rare
»	complete agates	40 to 90mm
»	most common size	50 to 60mm

Value per kg

»	selected rough nodules	R	12-00
»	cut half nodules	R	60-00
»	cut and polished half nodules	R	100-00

2. WOLMARANSSTAD

Soutpan Diamond mine. Operational alluvial diamond mine. Mechanical excavations 6 to 10 metres deep. Mainly full agates found on the waste dumps extracted from the diamond gravel. The origin of these agates is unknown.

Dark blue grey pitted outside with signs of erosion, also rounded pebbles. Inside white, grey, blue or black bands and lines within grey or brown chalcedony. Cavities often lined with quartz crystals and sometimes centre of crystals filled with chalcedony.

Size

»	fragments	10 to 15mm
»	complete agates	30 to 160mm
»	most common size	70 to 90mm

Value per kg

»	selected rough nodules	R	35-00
»	cut half nodules	R	120-00
»	cut and polished half nodules	R	180-00

3. LICHTENBURG

Pienaars Pothole diamond mine. Alluvial diamond mine, mechanical excavations up to 40 metres deep. Open cast mining process. Rehabilitated early 2004, and all dumps containing superb carnelian returned to the open pit. No new supplies available.

A beautiful yellow, orange, red or brown semi-translucent chalcedony, which originated in volcanic rock and transported within the alluvial diamond gravels. Always worn and eroded or smooth pebble on the outside. Mostly fragments. Full carnelians with patterns inside are scarce.

Size

»	fragments	5 to 50mm
»	complete agates	50 to 80mm
»	most common size	10 to 30mm

Value per kg

selected rough nodules

10 to 40mm

40-00

40 to 80mm

45-00

cut half nodules

------

cut and polished half nodules

200-00

4. LOCH VAAL

Vaal River alluvial diamond diggings. Old excavations completely eroded. Mostly farmland at present. Agates remained on the surface when mining was abandoned. The area is reworked at present and access to the collecting sites is prohibited. Only existing stock available.

Agates are dark to light brown to buff or sand outside. Many are eroded by water and smoothly rounded or the outside is weathered to powdery yellow or white. Various types of agates coming from unknown different locations were transported and mixed in the sedimentary gravels. Full modules are not plentiful.

Size

»	fragments	40 to 50mm
»	complete agates	60 to 170mm
»	most common size	70 to 100mm

Value per kg

selected rough nodules

10 to 40mm

14-00

40 to 70mm

20-00

70 to 100mm

32-00

100mm+

40-00

cut half nodules

------

cut and polished half nodules

180-00

5. JOZINI

Agates are found in the eroded remains of an ancient volcano and are distributed throughout the area.

Outside light to dark brown, rough sandy appearance. Round modules usually with flat bottom. Inside lower part horizontal layers of white red grey yellow brown or black chalcedony and upper part faintly banded or filled with quartz crystals. Often translucent. Good quality agate is hard to obtain.

Size

»	fragments	20 to 50mm
»	complete agates	30 to 100mm
»	most common size	30 to 50mm

Value per kg

»	selected rough nodules	R	25-00
»	cut half nodules	R	75-00
»	cut and polished half nodules	R	125-00

6. ZULULAND

Huge agates originating from ancient eroded basalt are found in the Maputaland Midlands. Most known locations are reported exhausted and no new ones discovered for the last 25 years.

Outside rough skin agates, dark or translucent exterior. Inside uniform grey to dark grey chalcedony with some bright colour inclusions or some horizontal banded layers in soft grey or pink and sometimes red. The huge agates are sought after and presently very scarce.

Size

»	fragments	50 to 150mm
»	complete agates	100 to 600mm
»	most common size	120 to 180mm

Value per kg

»	selected rough nodules	R	36-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------

7. VIOOLSDRIF

7.1.	BLUE LACE AGATE
	Open cast quarry, 15 metre deep with one single seam of gem material. Extremely difficult mining operations through solid granite. The remaining reserves are limited. No other deposits have been discovered.
	Translucent chalcedony with horizontal blue and white bands, linear material. Cavities and circular bands are very rare. Dark blue is the best quality and common blue lace is light blue with wide white bands. The material breaks up along natural shrinkage cracks.

Size

»	Slabs - most common size 40mm thick, 100 to 150mm across

Value per kg

»	selected rough nodules	R	65-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------

7.2.	CRAZY LACE AGATE
	Large modules of crazy lace agates are collected from the sand layers in the vicinity of the blue lace quarry. The mixed colours are white yellow brown and dark red. The agates also contain loose particles and pockets of clay. A beautiful gemstone but unfortunately limited resources.

Size

complete agates

100 to 200mm

Value per kg

»	selected rough nodules	R	115-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------

8. HOBHOUSE

The agates eroded from the gravels transported and deposited by the Caledon River. The gravel also contains other gemstones and diamonds and occurs in a vast area along the present Caledon River. Two different types of agates are found together although they are believed to originate from different areas. The origin of the agates is unknown.

8.1.	BLUE GREY AGATES
	Mostly fragments, full agates are usually small to very small. Blue grey and translucent outer skin, smooth, finely pitted sandpaper look to coarse. Black and white and grey bands in translucent chalcedony. Chatoyancy very common. Widespread on the farms along the Caledon River.

Size

»	fragments	20 to 50mm
»	complete agates	30 to 90mm
»	most common size	25 to 40mm

Value per kg

selected rough nodules

20 to 40mm

18-00

40 to 90mm

28-00

cut half nodules

65-00

cut and polished half nodules

115-00

8.2.	BROWN AGATES
	Brown rather smooth outer skin with sharp white to grey bands in translucent chalcedony. The finer bands display chatoyancy. These agates seem to be deposited in a gravel layer about 2 metres below the surface and are only found eroded on the sides of outcrops or during new excavation. A sought after agate, very limited supplies.

Size

»	fragments	40 to 60mm
»	complete agates	40 to 110mm
»	most common size	40 to 70mm

Value per kg

»	selected rough nodules	R	35-00
»	cut half nodules	R	65-00
»	cut and polished half nodules	R	125-00

9. MUSINA

Very small translucent red and pink agates and fragments are widely distributed in the topsoil of the Musina area. The favorite collecting sites are the sandroads where the car tyres and rain erode them from the soil. The resources have not been quantified.

Size

»	fragments	3 to 10mm
»	complete agates	10 to 20mm
»	most common size	5 to 10mm

Value per kg

»	selected rough nodules and fragments	R	30-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------

10. TSHIPISE

Fragments of sandonyx displaying colourfull brown and white bands are wide spread on gamefarms near Tshipise and can be collected when the grass is dry and very low or ideally after a veld fire. Most fragments are eroded and very seldom is a complete module found.

Size

»	fragments	10 to 40mm
»	complete agates	20 to 25mm
»	most common size	10 to 20mm

Value per kg

»	selected rough nodules	R	35-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------

11. AMALIA

11.1.	GREEN AGATES
	Small to very small green agates have been found on a small outcrop, possibly vulcanic, on one of the farms. Could have been formed where they are found. These agates are extremely rare. Only 40 specimen were collected in the last 20 years. A sought after collectors specimen.

Size

»	fragments	5 to 15mm
»	complete agates	5 to 30mm
»	most common size	10 to 20mm

Value per kg

»	selected rough nodules	R	950-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------

11.2.	AGATES
	Mostly full agates are recovered from an ancient riverbed, now situated on a game farm. The agates erode out of the soil. No other gemstones have been found with them. Yellow brown to light brown outer skin, heavily crusted and pitted, with distinct black grey and white bands in semi-translucent chalcedony. Most fragments are eroded by water.
	The origin is unknown, but the condition of the modules indicates that they were not transported over a long distance. No other deposits of the same variety are known.

Size

»	fragments	20 to 50mm
»	complete agates	20 to 60mm
»	most common size	20 to 40mm

Value per kg

»	selected rough nodules	R	40-00
»	cut half nodules	R	80-00
»	cut and polished half nodules	R	135-00

12. PRIESKA

Small carnelians erode from the soil along steep riverbeds in the Prieska area. They are weathered yellow, red and brown and sometimes translucent on the outside. Inside yellow reddish and brown with some bands and inclusions. They were transported by water but nobody knows from where.

Size

»	fragments	10 to 25mm
»	complete agates	20 to 40mm
»	most common size	15 to 25mm

Value per kg

»	selected rough nodules	R	50-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------

13. LESOTHO

The agates are found in the Rivers of the Maluti Mountains. They were formed in the Drakensberg Basalts (volcanic rock). Mainly fragments are found.

White chalcedony outside and rough pitted skin. Inside mostly white bands in grey to blue Chalcedony. Translucent and sometimes transparent.

Size

»	fragments	20 to 100mm
»	most common size	50 to 60mm

Value per kg

»	selected rough nodules	R	30-00
»	cut half nodules	R	------
»	cut and polished half nodules	R	------