Gems FAQ – to learn more, click on a topic


Paladin | Pendant Moser PyroAmetrine is a trade name for a naturally occuring combination of purple Amethyst and yellow Citrine in a single Quartz stone. The color variety is due to different degrees of oxidation of the mineral’s iron content, and results from temperature variations in the mineral during formation. Origins of Ametrine are Bolivia and Brazil. Over the past two decades, Ametrine has become a scarce mineral. Pictured: Ametrine pendant by CADEAUX Jewelry. Gem sculpted by late Swiss-Australian gem-artist Bruno Moser.

Black Jade

Cult | Ring Il MagnificoBlack Jade is a common name for Augite, an opaque, jet-black, and shiny mineral that is of eruptive origin. Its greenish-white cousin from Burma, which owes its color to its chromium content, is the more well-known variety, revered as Jade, Imperial Jade or Jadeite. Main origins are Burma (green Jade), China, Guatemala and Mexico (Schumann). Pictured: CADEAUX Jewelry Il Magnifico rings in 18-karat gold, with skulls carved from Black Jade (left), Chalcedony (belwo) and Turquoise (right).


Cult | Ring Il MagnificoChalcedony in a wider classification includes micro-crystallic structured Quartzes (Silicon Dioxides) like Carneol, Jasper, Chrysoprase, and Jasper. More narrowly Chalcedony refers only to the white-grayish and bluish translucent stone. Chalcedony is popular for carvings as well as for beads. Main origins are Brazil, India and Madagascar (Schumann). Pictured: CADEAUX Jewelry Il Magnifico rings in 18Kt gold, skulls carved from Chalcedony (below), Black Jade (left) and Turquoise (right).

Dendritic Quartz

Dendritic Quartz is a silicon dioxyde, in its white-grayish and translucent form also called Chalcedony and characteristically marked with a dark-brown matrix. The patterns resemble trees or ferns. Hence dendrite or dendritic, terms that derive from the Greek “dendron” (tree). The dark-brown patterns are iron secretions and manganese oxides that have oozed into fissures between thin Chalcedony layers. Main origin is Brazil (Rio Grande do Sul), USA and India (Schumann).

Lapis Lazuli

Lapis Lazuli is famous for its blue color, often referred to as indigo, royal, or midnight blue. It is an opaque aggregate of Lazurite, Pyrite and other minerals. Traces of Pyrite may be seen as sign of authenticity. In ancient times ground Lapis Lazuli was used in ultramine pigment. Origin: the Hindukush mountains in Afganistan; other sources are Pakistan, Chile, Siberia, Angola, Canada, and Colorado (Ostendorff; Schumann). Pictured: Lapis Lazuli ring by CADEAUX Jewelry. Gem sculpted in the shape of a scarab.


Rubellite is the reddish pink variety of Tourmaline, occasionally with a violet hue. The most valuable color is “Ruby-Red”. Historic origins are the Ural Mountains, Elba and California. (Ostendorff). Pictured: CADEAUX JEWELRY’S Paladin series features a truly irreplaceable ring with a 42 carat Rubellite engraved by German gemstone artist Erwin Pauli with an image of Cleopatra, queen of Egypt (69 BCE to 30 BCE).

Rutilated Quartz

Rutile is a mineral (Titanium Dioxyde), which crystallizes in long needle-like structures of red (“rutilus” meaning red or golden reddish in Latin), golden or metallic color. Rutile is often embedded in metamorphous rocks, meaning in rocks that have changed shape typically through the process of crystallization, such as Quartz. Main origins are Norway, Brazil, USA. (Ostendorff). Pictured: CADEAUX JEWELRY’S Paladin extraordinary SPHYNX ring in 18 Kt gold with a Tourmaline cat’s head and a Rutilated Quartz torso, also set with yellow Sapphires, Rubies, Diamonds.


Tanzanite is a commercial name for blue Zoisite (Calcium Aluminium Silicate) first used by an American jewelry retailer. This variety of mineral was discovered in Tanzania, Africa in the 1960s, hence the name. In lustre, color and clarity it can often compete with Sapphire, however, it does not have the same characteristics, especially in terms of harndess. The most sought after color is a deep ultramarine blue, but often this gems has a slight violet tinge. (Schumann). Pictured: A beautiful natural Tanzanite crystal of 61 cts acquired by CADEAUX JEWELRY in 2011. This crystal is being mounted in a piece of jewelry as is, uncut and unpolished.


Tourmaline is a complicated mixed crystalloid configuration that yields the biggest variety of colors among all gemstones. Green is the best known color, culminating in a much sought after saturated green referred to as Chrome Tourmaline, but Tourmaline occurs also in a variety of reds, pinks and violets (Rubellite), and in blue and white hues. Historic origin of Tourmaline is Ceylon (“tourmali” being a Ceylonese term of unknown meaning), Brazil, and Africa. (Ostendorff; Schumann). Pictured: CADEAUX JEWELRY’S Paladin extraordinary SPHYNX ring in 18 Kt gold with a green Tourmaline cat’s head and a Rutilated Quartz torso, also set with yellow Sapphires, green Tsavorites, Rubies, Diamonds.


Turquoise is a Copper-Aluminum-Phosphate in the Apatite family that often occurs in form of boulders that have an opaque oily luster and a greenish-blue hue. Because Turquoise also contains water, it is susceptible to exposure to heat and to contact with cosmetics or other chemicals, which may all cause discoloration. Thus Turquoise jewelry should be spared contact with cosmetics and removed while washing with soap. The name Turquoise derives from the old trade routes that brought the stone to the Occident via Turkey. Main origins are Persia (Iran), Afganistan, China, Tansania and Florida (USA). (Ostendorff; Schumann). Pictured: CADEAUX JEWELRY Cult series Il Magnifico rings in 18Kt gold, skulls carved from Turquoise (right), Chalcedony and Black Jade.


Sources: The information on this webpage, unless mentioned otherwise, is based on Edelsteine und Schmucksteine (Schumann, W., BLV Verlagsgesellschaft, München, Bern, Wien, 1976; referred to as “Schumann”), Steine in Farben (Ostendorff, E., Otto Maier, Ravensburg, 1966; referred to as “Ostendorff”), and the website of Gemological Institute of America, GIA. Photos: CADEAUX Jewelry.