Onycha (pronounced ON-ee-kah) is the operculum of a sea mollusk used in sacred incense formulas around the world.

These are from the Red Sea. Onycha is added to incense as an exultant and fixative. They are low in shellfish odor, clean and light. There are many ways to prepare them, from soaking in Rose oil to the methods mentioned here, and also Be-en-Foret's way (see the link to her unique article below)

 

On Onycha:

         Onycha is a mysterious incense ingredient mentioned in the Christian bible; Exodus 30:34:

And the Lord said to Moses, “Take sweet spices, stacte, and onycha, and galbanum, sweet spices with pure frankincense (of each shall there be an equal part), and make an incense blended as by the perfumer, seasoned with salt, pure and holy; and you shall beat some of it very small, and put part of it before the testimony in the tent of meeting where I shall meet with you; it shall be for you most holy. And the incense you shall make according to its composition, you shall not make for yourselves; it shall be for you holy to the Lord. Whoever makes any like it to use as perfume shall be cut off from his people.”

 

       The reference does not give any indication as to what Onycha is so we must start with the name itself, which is a Greek word for “fingernail,” translated from the Hebrew, “Sheheleth“* and is applied to an operculum, defined as, “the claw or nail of the strombus or wing-shell, a univalve common in the Red Sea.” With the name of the ingredient meaning “fingernail” and/or “a univalve claw or nail” we can now examine the various theories around the world as to what this mysterious ingredient may be.

 

     The dried lids look like fingernails and since ancient times have been known to be widely used as a fixative in incense mixtures in India, Tibet, and Japan. Each prepares the opercula using different methods. In Japan the same ingredient is called “Kaiko,” and it’s soaked or slowly heated in a mixture of water and vinegar or alcohol to remove the shellfish aroma, then ground and used as a fixative in their incense mixtures.

 

In Tibet, the opercula lids are crushed, placed in a pan of oil and slowly heated to draw out a resin from the lids into the oil. This resin-filled oil is then used in high-quality incense mixtures. In India, the lids are slowly heated in Ghee (clarified butter) several times until they are golden in color. These are then dried, crushed, and used in high-end incense mixtures as a fixative.

If we trace the origin of the Exodus mixture itself, to the Hebrew Qetoret, we find that there are sixteen ingredients in the incense recipe given to Moses (see Qetoret). In it, Onycha is “rubbed with Karshina lye to make it more pleasant and then soaked in Cyprus wine to make it more pungent.“

 

Read Be's article and thoughts on Onycha